I might be wrong here, but I think the biggest reason for this is that Europe hasn't really produced a tech company in the past ~25 years, with revenues (and profits) amounting to anything close to those of the FAANGs.
OTOH, there is the separate issue of FAANGs not compensating their European workers as well as they do the ones working in the US.
> OTOH, there is the separate issue of FAANGs not compensating their European workers as well as they do the ones working in the US.
They don't, but they do compensate them similarly relative to the local average pay. They pay what they need to to get the talent they want.
I work at Google Munich, the pay here is much higher than a regular company in Munich, similarly to how Google pays much more than a regular company in the US. In some ways the difference is even more striking here, because there are few peer companies here that pay similarly to Google (there's a Lyft office, and a small number of Amazon devs, that's about it AFAIK), whereas in major tech hubs in the US you usually also have Facebook and Apple and Amazon and Microsoft and Netflix and various others that are similar or close.
Sure this makes sense, and I've heard rumblings that the average pay in the Berlin startup scene has been climbing these past few years. But I guess we're still far away from someone with five years of experience making 400-500k per year.
Sure, but that's small consolation if you're not able to capture the value. That said, as a Finn, I'm quite happy about Linus Torvalds.
Still, almost all industries will be tech-enabled in the future (software eating the world etc.), so one would expect European banks for example to up their game when it comes to tech salaries. Alas, it seems that they're are also quite poorly run [1], so I wouldn't hold my breath.
Also, apart from Spotify, European tech workers haven't been able to enjoy the benefits of the streaming wars. And even Spotify is hamstrung by relatively low margins due to high licensing costs [2].
I guess the one industry that might have already increased their rates for SWEs is the car industry and specifically, the relatively profitable German car brands. But it seems they're more focused now on producing electric cars rather than creating online services [3].
As a European tech worker, if you're not willing or able to move to the US, two good options can be to get involved with local startups or to go into independent consulting. Maybe a little ironically, the opportunity costs of starting or working for a startup in Europe might be lower than in the US, due to the smaller pay gap.
OTOH, there is the separate issue of FAANGs not compensating their European workers as well as they do the ones working in the US.