Anyway I know of plenty of people who landed remote jobs at US companies, or US-based companies opening offices within Europe. I mean most US companies operate through Ireland, the Netherlands and Luxembourg anyway because of tax evasion.
Except high taxes its an issue though but for the company's taxes, not the employees' taxes. You even said it yourself later ["I mean most US companies operate through Ireland, the Netherlands and Luxembourg anyway because of tax evasion"] it just so happens that the countries with low corporate taxes also have low income taxes and countries with high corporate taxes usually also have high income taxes.
There's a reason why all big tech in EU is parked in those countries with low taxes and simple laws like Luxembourg, Ireland, Netherlands and not in countries with high taxes and complex laws like France, Belgium, Austria, etc.
And no, most big tech don't really hire EU-wide remotely outside of their HQ country and a few select other countries since we have no standardized EU wide corporate and workers' laws so a lot of EU countries get left out due to their stricter laws.
Depends, it's not just about the employees salaries. Some EU countries have pretty high taxes and high worker's rights so big tech actively avoids them.
So in the grand scheme, Indian offices might yeld better return on their investment.