I just said "Lemmy" and they went forward from there.
Helping people pick an instance is not as straight-forward task as many people claim. e.g. if you love programming, then perhaps programm.dev is right for you, except right now they are having enormous federation difficulties - e.g. https://programming.dev/post/20692281. They are far from the only ones doing so though - https://feddit.org/post/3524876 - and yet they do have more difficulties than most.
Any instance that is not Lemmy.World itself is going to suffer right now, until the deployment of 0.19.6 - https://github.com/LemmyNet/lemmy/pull/4623. And yet people piling on top of the already too-large pile of Lemmy.World will only make the future problems worse. This whole "federation" concept is still experimental, compared to a single-server model like Reddit had.
Blaze often tells people to go by default to lemm.ee. Which is one of the rare instances that defederates from none of hexbear.net, lemmy.ml, or even lemmygrad.ml. So if someone comes across this advice and follows it... BTW, Lemmy.cafe likewise defederates from almost nothing, except it DOES defederate from those big 3 (caveat: it seems run by only a single administrator, so is therefore far less stable than e.g. lemm.ee, and could disappear at any time - though there are so many other things about that instance that are so welcoming and friendly, and btw it is one of the very select few that are already running 0.19.6-beta! so a single admin yes, but one who seems VERY on the ball!).
But ultimately you are correct: they control the sourcecode, so it is YOU who are using THEIR platform - and they WILL do it THEIR way, regardless.
Until and unless more people switch to Mbin, PieFed, or eventually Sublinks. Admiral Patrick who developed Tesseract for dubvee.org and who has blocked lemmy.ml users has pledged to switch to Sublinks whenever it will come out. In the meantime you can view a demo, but I haven't heard of any developments for it for like half a year. So I switched to PieFed, and am posting several bug reports to help make it better. I advise people to check all of these options out just to see what's out there, though definitely more is yet to come due to the hard work from these very helpful developers!
And credit where it's due: Dessalines is helping in his own way, to reduce people's dependency upon Reddit, and offering that codebase completely free of charge - that's not nothing. Though administering a server instance is an entirely different skillset... and if we want to see the Fediverse grow rather than shrink with time, I think that better fences are going to be necessary (or mere labels would be even better, except they seem to militantly refuse to do such - but could you imagine if "politically extremist" content had a label just like all the NSFW posts do? then we could all get along side-by-side in the same space).
Nobody enjoys being punched in the face, or to see their (or why not ANY?) nation mocked - especially normies who may have DEEP knowledge of their subject matter, yet happen to not use Arch Linux btw, or may not be actual full-on communists (yet?).
But please remember that in order to enjoy such diversity of opinions as you mentioned... we must become intolerant.
To the intolerant. There is no faster way to shut down conversations than to allow bullies to dominate everything within their reach.
So long as conversations can be kept "fun", there will naturally be many more to follow, but when they cross the line, then fun-time is over and the people go home. Unfortunately, modding efforts are in short supply here - not as limiting as content creation, but still a constraining factor.