On the Dart to Sandymount they’re talking about angels and unicorns. Which is strange, as they’re not five-year-olds. In fact pretty much everyone in the carriage is a 25- to 45-year-old man wearing the same uniform: suit jacket, no tie, jeans. The chat is also of VCs and VR, pivots and platforms, bootstraps and wearables. You’d need an app to translate this stuff.

My phone pings – again – with a notification from the Web Summit app. "Hi Hugh! I'm a 20 year old girl from Australia, co-founder of ClosetDrop – Rent out your wardrobe. To put it simply, we're basically the Airbnb of fashion. My best friend and I started ClosetDrop to help girls all around the world fulfil their expensive taste in fashion for just a fraction of the price. ClosetDrop is a global online market-place where girls can rent out their own clothes, shoes & accessories between each other . . ."

I’m still 10 minutes from the entrance, but I feel as if I’m already deep inside the forcefield of Web Summit. (The definite article is always absent, as with Fight Club or Electric Picnic, or Narnia). What is this strange place, and why does it exist?

Part evangelical prayer meeting, part digital flea market, it’s a mixture of the huckster and the hipster, and in its own way it provides a snapshot of a lot of the forces that, for good or ill, proclaim that they’re going to change your world.

And what exactly does the word tech mean? I like this description, by Nathan Heller: "Tech today means anything about computers, the internet, digital media, social media, smartphones, electronic data, crowd-funding, or new business design. At some point, in other words, tech stopped being an industry and turned into the substrate of most things changing in urban culture."

Through some happy conjunction of luck, timing, brass neck, hard work and sheer pig-headedness, Web Summit's founders, Paddy Cosgrave and Daire Hickey, tapped into that substrate over the past few years and built from scratch an international event that this year claimed an attendance figure of more than 40,000. Web Summit has grown and grown, and now it has grown too big for Dublin. Some might say it has grown too big for its bootstraps.

Irish media coverage this week has been as plentiful as ever – to the annoyance of those who regard the whole thing as overhyped in the first place – refracted through the prism of the absurd handbags that broke out between Cosgrave and the Government about who wanted what and who said whatever to whom in the months leading up to the announcement that Web Summit would be moving to Lisbon for the next three years.

It flared up again with rows about invitations and snarky interviews on radio and television.

Nobody came very well out of this small-town bickering, but it didn’t seem to have registered particularly with the international visitors I met this week. Talking to a cross section of them during the pub crawls organised across central Dublin on Monday night, one thing came across clearly, however. They did like being here.

It helped that the weather was better than it had been in August, but over and over I was told what a beautiful, interesting, friendly city I lived in. The impression was unavoidable that there’s a connection between Web Summit’s success and its location.

It’s something the Government would do well to pause and ponder, no matter how well the move to Lisbon works out. Because, whatever method you use to calculate the value of Web Summit to Dublin in cold, hard cash terms, and whether or not you buy into the proposition that it contributes to the growth of an indigenous tech sector, there is no doubt that these tens of thousands of people are highly educated, highly connected and potentially highly influential, which has to be worth something.

The people I talked to came from North and South America, from across Europe, the Middle East and (to a lesser extent) Asia. To my inexpert ear some of them seemed to be involved in substantial enterprises. One was helping to build a platform for the sale and distribution of education services and distance learning across the Indian subcontinent. Another was developing a digital marketplace for advertising inventory on digital billboards in Brazil.

Some of them, though, do fit the start-up cliche. Two young guys have an app that allows you to hook up and socialise with like-minded people when you're away from your own country. "So it's like Tinder for city breaks," I say, but their faces darken. Someone must have got to that line first.

All this frenetic activity, all these tiny start-ups selling variations on a theme: does it really amount to anything substantial? Henry Hwong, a Palo Alto-based marketing consultant, tells me that cloud-computing platforms like Amazon Web Services and Microsoft Azure mean there is a very low barrier to entry, which is the reason for the glut of "Uber for this" or "Airbnb for that" type of companies.

“It would be nice if there were more investment in really hard engineering projects that move technology forward,” Hwong says. “But that’s just technology capitalism, and Darwinism, at work – lots of investment in many companies that will go nowhere, but the ones that succeed could have a major impact on society.”

At the RDS over the succeeding three days the sheer scale of Web Summit now creates its own dynamic. With so many stages operating simultaneously, and so many different “summits”, each with its own rows of start-ups pitching for business from cramped plywood booths, this year’s event starts to feel as if it has split in two, with one Web Summit in the main RDS complex and the other across Anglesea Road in Simmonscourt.

As the Irish Times columnist Karlin Lillington pointed out, too many of the events are just too short, and therefore don't go deep enough to yield anything truly interesting. But, despite all the self-aggrandisement and messianic claims of changing the world, there are plenty of thoughtful, impressive people with something to say.

Then there's the Food Summit in Herbert Park. In previous years this was an impressively organised series of tents feeding thousands of people excellent Irish food, with front-of-house duties carried out with aplomb by the likes of Darina Allen – all included in the price of your ticket.

That you had to pay an extra €20 a day this year, and that the quality of the food seemed to have fallen significantly, provoked some angry reaction. The tents looked grim and empty compared with previous years, and the organisers stood accused of price-gouging – the very charge they had levelled at Dublin hotels.

Who knows what Web Summit will be like at the end of its three-year stint in Lisbon? Cosgrave seems to model it, and the spin-off events he now runs in other countries, on the digital-business model of scaleability, where rapid growth and the acquisition of new customers are the overriding imperatives.

He may be right – and there are other successful events internationally that outrank Web Summit in size. But human beings aren’t software, and the impersonality of a purpose-built conference facility on a city’s fringe could drain away some of the improvisational and occasionally ramshackle elements that made the whole thing work in the first place.