It’s naive to think that regulation is going to cover the entire global internet.
If you regulated domestic companies out of existence, global options would pop up in their place. You could try to block them all in app stores but people would go to the web views.
I think that's still mostly fine. Youtube is already not an app but a web site (It has apps too but I think it's less app centric than e.g. instagram).
Obviously we need the ability to regulate also global options. Typically if these actors truly become big, then they have a presence in their "target" countries, such as ad sales.