This is where I disagree. I say that people have a right to speak (and not be hassled by the government for speaking) but that does not imply that people have a right to be widely heard. This means the people who own the "megaphones" are free to regulate who gets to use them. Don't agree? Build your own megaphone and work to make it bigger. People do not have a right to free ride on other people's megaphones. Or to put it in old-school terms: You have the right to publish a book, but you don't have the right to get it into every book store. Or to start earlier, you have the right to write a book, but you don't have the right to force someone else to mass-print it.
This implies that I definitely favor the old mass media style "gate keeper" role. Incidentally, since what I mean by "gate keeper" apparently wasn't obvious, I meant serving as a filter of certain ethical standards. To elaborate, in order to publish in a science magazine, the author has to abide the scientific code of conduct; in order to publish in a newspaper, the person has to abide the journalistic standards; and so on... This avoids bad actors free-riding on the goodwill that the gate keeper has otherwise established.
(Part of the problem here is, as I described above, is that a lot of the goodwill up from a history of following these codes has been capitalized/monetized. E.g. news organizations have admitted "opinion" pieces to such a degree that many people can no longer tell the difference between an opinion host and a news host ... all the while the news outlet continuing to pretend that it's a news outlet rather than a propaganda outlet for a certain opinion... resulting in many functionally incapable of differentiating between facts and opinion in general or putting the latter above the former. Ditto web2.0 sociopaths capitalizing on the overall helpful friendly and truthful environment of expectations that the web1.0 nerds built up.)
This does not mean I could not see companies or organizations going into the business of lending their megaphone to everybody with no exception. The *chans, Parler, ... and other "free speech"-sites have famously or notoriously profiled themselves on that. However, the market also shows that there's relatively little demand for their services. In other words that particular free-for-all megaphone will be a relatively small one. IOW, it'll be a soap box in the town square rather than an appearance on national TV. FWIW, I also remember the existence of publishers willing to publish what most other publishers wouldn't touch with a ten foot pole. These publishers were obscure but because of the first amendment they did exist.
In short: Just because something becomes popular does not mean it becomes public!