Its not true right now.
Since you live in Europe than you know that Europe is great in heavy industries like car engines, cars, planes, factories and in general B2B (business to business) services. Heavy industries now sucks ass. Really.
Europe is missing so called Digital Single Market. there are no unicors. NADA, ZIP. You could say maybe German SAP, maybe one. If there was good digital player then it was bought by US like Skype from estonia was bought by microsoft. Take a look at electronics in BMW - is just pure crap. US on the other side has the scale and software. Since most of the world right now work remotely using teams (microsoft), office 365 or Google G suit then this is why those big tech are proliferating. same as Netflix. They closed cinemas and entertainment is moving to VOD (video on demand). In Poland several films which were suppose to be put in cinemas were streamed in polish VOD apps. its a revolution. Now there is a war. Just this week biggest cinema operators went against Uiversal because they want to change the model - no exclusive rights for cinemas. in the same dates you would stream film in VOD
COVID-19 just turbo charge the big tech trend and US is the biggest beneficiary of that. Thats a fact. Pure fact and you dont need any FED liquidity to pump up this stocks. You have to be invested in big tech since they are wining. really. The question is - when they become to big and they will be split like AT&T. the talk is ongoing, but the question is - how to split them. they are not railways, you cant separate lines. Look at Amazon -> 70+ bln USD rev in Q1 2020, with AWS cloud (10bln USD). they had earnings -> 3 bln USD but 80% of that came from cloud. rest of amazon is ....generating loss! its cloud, gaming, office365 which is scaling. not shitty eCommerce since you need to hire 100k people.
So big tech is moving market. They have sound and good fundamentals. of course the question is PE/valuation. But the trend is real.