IMO the issue isn't so much the taxation, although this has a big impact on hiring since you need to be very certain about anyone you keep past their trial period.
The bigger issue is that the US has a massive advantage, in that a US tech company can launch in one language (their native language) to 300+ million potential customers, and hire from the same pool with minimal bureaucracy (the laws are largely the same, and at least written in the same language, ID and visa requirements are the same, payment providers are mostly the same, etc.)
In Europe on the other hand, to launch even to other countries in the EU involves a lot of translation work. Then taxation varies a lot, and the laws are in different languages so you'll need local lawyers and a local tax office to hire employees there, etc. - on the employee side, the ID and visa requirements vary a lot too, so you'll need local specialists / relocation companies to help with that. The payment providers also differ a lot, e.g. with Sofort-überweisung in Germany and the lack of online card payment options there (until recently), etc.
And then there's the extra EU regulations - the GDPR, cookie consent laws, age verification laws for video content, link tax for aggregation services, etc.
But I still think the best solution in the short-term is protectionism. Give European companies a bigger advantage in Europe by not sourcing from foreign corporations (especially for critical infrastructure like public services), and invest in FOSS and development companies around that (where smaller companies could work together on FOSS projects).
Otherwise the US companies just dominate, and then use their dominant position to get a monopoly through bribes and threats (see Microsoft in Hungary and Munich for example). Then they pay no taxes in the EU, take all the profit back to the US and use that to crush EU industry even further - just like how in the past natural resources were plundered from colonies, but all the skilled industry was kept in the coloniser countries.