Thr answer to US tech giants are not homegrown EU tech giants, but international free software (Free as in Freedom). We already have free operating systems: Linux, BSD. Office software: LibreOffice, etc.
EU regulators have stop listening to tech company lobbyists.
Is any of that capable of replacing google and apple on mobile?
We need competing (and competent) lobbyists. Unfortunately one side has all the money, so there is a clear disadvantage