But if you compare the averages then yes you’ll be lucky breaking $70K in the EU.
The average compensation for engineers is about £100,000 - some above and some below. This is on top of private medical and dental, generous pension contributions and a number of other benefits.
Outside of the UK you might be lucky to get €50-60K even when working for US firms on average this includes Germany.
Some Nordic countries have higher salaries but the CoL is pretty steep.
Overall if you don’t include taxes it’s possible to get competitive salaries in the UK and some parts of Europe once you take into account income tax and VAT you’ll the race isn’t nearly as close anymore.
Also startups do not pay well at all and equity is nearly unheard off even for single digit non-founder employees.
Seriously here in Norway getting over 100K € annually is becoming normal. If you are really talented, then you can even make 150k € annually. Freelancers make over 200k € annually. There is a huge shortage for developers these days, much thanks to "digital transformation" trend.
Norway has a higher cost of living due to the 25% VAT, and because the national (non-developer) median salary is so high. Not to mention vehicle and gasoline taxes.
If you are very clever with applying taxes, and you don't pay into a private pension then you might be better off- but it's a good thought exercise to apply the costs of living differences and then work out what level of flexible income you have left, and then what buying power you have with that money.
The quality of life is generally comparable for jobs which technically pay 2x a UK salary in the USA.
That doesn’t sound right - $100k USD for a good software engineer is about right for second tier US cities where rent, taxes, and food are lower than in England.
You get bit at both ends - you had to pay for an American college degree ($$$) and had none of the social services like unemployment benefits/worker protections someone in the EU gets... then when you finally are making a high wage, you're going to get taxed to high heaven to pay for services you had to pay for (like the expensive degree I just mentioned).
Sadly, the best move looks to be to be frugal in the USA then retire early elsewhere.