Berlin is now in a position to usurp London as the startup capital of Europe

Purely anecdotal, but London is regularly referred to as the FinTech capital of Europe, and it often seems to be because London doesn't have a lot of startup success stories to boast about. For me, the startup buzz in the UK tends to be smaller outfits away from London, either close to top universities (Oxbridge) or in larger cities with an existing digital culture (Bristol, Manchester).

Again, purely anecdotal, but I know a few people that have moved from London to Berlin, and they couldn't be happier.

That's exactly the point, and something I don't think many British people realise. (I don't think Americans etc realise it either, but I don't expect them to.)

Moving to work in a different EU country requires what I'd guess is a similar amount of paperwork as moving between US states.

- Register your address with the local government (which may lead to an id card, tax registration etc) - Update your driving license, if applicable - Tell the old country you'll stop paying tax there (may lead to a tax refund)

These are the same kinds of processes as are used when a child is born, a teenager gets a first job, or an adult moves house. Nothing requires permission, nothing can be refused.

Additionally, there are agreements for things like state healthcare, pensions and out-of-work benefits.

If the UK raises barriers, then London will be less appealing for other European citizens.

Saying they get ~ 50k euros/year but don't worry, the cost of living is low is a universal non-starter. That's just simply not competitive. The cost of living is not so low that a person can reduce their salary to around 1/3 of what they could make in New York or SF and expect to have the same quality of life.

You're basically handcuffing one arm behind your back by basing yourself in Berlin (or many other places) because now your pool of applicants is limited to only those people who have some ulterior reason to be interested in living in Berlin and are willing to make a Faustian bargain regarding huge reduction in their wage (even relative to cost of living).

Stockholm is pretty great when it comes to technical and investment maturity. We blew through and did all the stupid dotcom stuff in late 90's, while some have been repeated many successful entrepreneurs learned from that time. Internet access has been really good leading to a lot of good technical talent. It's a beautiful city that want's to be "international" and overall things are very polished. Sweden's also has a track record of producing a few gigantic hits such as Spotify, Soundcloud, Klarna, Skype, Minecraft etc etc.

On the downside the housing situation is insane and everyone has borrowed to the hilt trying to keep up with the ever increasing prices. You can't get hold of an apartment without buying. It's also a pretty expensive place to live. It get's pretty dark & pissy in the winters but summer's are great. I used say that living in Stockholm is 9 months of wondering why the hell you live here and three months where you get the answer.

Berlin in contrast feels like something very unique in Europe and Germany. It's like melting pot of different countries and not quite grown up mentality. Housing is still relatively accessible and affordable, there's even rental contracts to be had. Food and drink is overall cheaper. The startup spirit in Berlin still felt a bit naive when I was there, like a first wave city, but it's big and enthusiastic. However they seem to struggle to product big hits outside of their own country. Maybe the difference between Sweden and Germany is that Sweden is so little we have to go international, and also we're more anglofied. Big companies generally haven't been so big on Berlin since they don't have an international airport, leaving the city wide open for everyone else. On the downside Berlin is a bit meh when it comes to scenery and nature.

Outside the tech scene the English in Berlin is pretty bad and some look down at any not speaking German. Swedes grow up with English and most love every opportunity to use it.

I think there's a good bet Berlin will start to dominate as a "Silicon Valley of Europe", if nothing else because there's a vacuum there that can be filled, and it will become even more international than german. Even Swedes look at Berlin simply because it's cheaper and more accessible. It also has a bit bigger scene when it comes to small "startuppy" kinda ventures while Stockholm dominates on the more serious ones.

Working as an employee seems to suck in Berlin because everyone is looking for a job and job's pay poorly. But if you work for yourself and/or with investment money that doesn't matter and you're in a good position to leverage that money.