Of course, that last bit is changing (which is part of why you’re asking the question, no doubt).

maybe? :)

And that’s the answer to your question. If those services go away, they will be replaced by something else.

I would be tempted to agree (while also recognizing a minority (like myself) would try to steer away from anything remotely looking like a clone of those 'original models' and rekindle the interest for a smaller more fragmented Web) but, at the same time, suffice to see how that less-democratic USA we now have to live with is dealing with anything that even remotely looks like a threat: invading a country, taxing it do death (unless they withdraw any law deemed unfair for US businesses),... I doubt those USA would allow any serious alternative to grow and to reach a large enough audience... But then, in my first hypothesis and for some mysterious reason we would already have lost access to US tech/services, and therefore one may conclude that at the same time USA would have lost access to us as a potential market and wouldn't have any leverage against our own attempts, well, maybe? ;)

but nothing lasts forever.

Not even empires, or wannabe new empires. But isn't it what history is all about: failed dreams of grandeur?

edit: typos.