The problem is that Jack and his buddies will happily kneecap competitors. So the whole 'if you don't like it, start your own X' meme falls apart, because you are prevented from doing so.
Well, if
Parler had done it right from the get-go they wouldn't be in the situation they are in now. They hosted their entire site on Amazon Web Servers. Literally, doing it the old fashioned way means setting up your own data centers, and then having neutral international DNS providers like Switzerland, Samoa, Netherlands, Iceland, etc....
Robert Mercer funded
Parler, and he has plenty of cash reserves, but Parler didn't spend the money on building their own infrastructure and truly serving as a neutral internet host. Instead they subcontracted, and not even to the lowest bidder.
Examples of other Companies that did setup their own hosting includes
Wikileaks,
Pirate Bay (But they had to learn the hard way not to trust Sweden and Norway),
The Silk Road, and
Mega, in New Zealand. None of these are shutdown, however according to kim.com Mega has been effectively seized by the NZ government, although there is no evidence they are interfering with its operation..