There are tons of Lemmy instances, so figuring out the right one isn’t as straightforward as stumbling upon a single central platform.
I'm arguing that it's exactly as straightforward as picking between Twitter, Reddit, Facebook, Instagram, Pintrest, any website. How did these people who can't search find reddit? I get that it sucks leaving a company you have a relationship with. I just don't think it's hard, and I do think that the last 20ish years (at least) have shown that companies are "take it or leave it", and rarely if ever respond to requests no matter how you make them. So it's back to my initial point - you shouldn't want a "central platform" because eventually it becomes worse and worse. This holds true in theory (monopolies are bad) and practice over recent and longer history.
I guess I also don't get the concern about picking "the right lemmy instance" - at worst, it's like picking an e-mail server, or grocery store. Try a random one, find out what doesn't work for you (if anything) and then use that knowledge to evaluate the next one. Repeat until happy. In reality - that's also what we're doing up a level in terms of platforms in general - I was happy on reddit till I wasn't. Presumably same for everyone. Many people might still be happy on reddit. I don't judge that - my beef is if you're extremely unhappy and yet basically want someone to change reddit for you vs moving on.
I am NOT at all arguing that it's not difficult to move entire communities at all. I'm not sure if it's possible - you're going to basically fork no matter what. And that sucks, but it's also something the community risked (and always does risk) on a given platform if it becomes crap for some reason. A community is also never fixed and your reddit community is changing no matter what with the various things going on. I don't know how big a change it will be for any given community, but to the extent you're empowered by the central platform, you're losing some people (those like me) to alternative platforms. You can't stop that. Heck, even without reddit doing their best to burn their platform trust to the ground, there were always going to be people who move along, try and make a spinoff community either on reddit or elsewhere etc. You can't have a unified approach unless a large majority agrees to either live with reddit or to leave reddit to the same place. I don't think either is actually going to happen in the long run.
And software wise, I think as you have pointed out it seems reddit wants to make things kind of worse and lemmy and the fediverse is trying to make things better. So over time, just like how lemmy is WAY more active now than it was a month ago, I think we'll see the software improve too. So maybe today it's really in reddits favor to stay there as a mod - though I know /r/photography didn't agree - but I feel like each day those lines are getting closer together where you'll cross and probably end up with 2 viable communities, and one isn't on reddit and everyone has to choose if they want to be on both, or one or the other. The main thing is lemmy and the fediverse are all in on API access and anyone writing tools, and reddit has closed that off basically entirely. So as I understand it, there's very little chance to get mod tools back on reddit, but there's every expectation that people are building mod tools for lemmy. That's not to say a closed system is inherently bad - but I've rarely found it to be the most inexpensive or option filled. I also heard a recent techdirt podcast on distributed moderation and reddit and that all their public competitors have (had? Twitter got rid of theirs but went private) professional trust and safety moderation teams, and there's a good chance that's going to be something wanted for an IPO by investors expecting legal or regulatory risk, and with that will be a push for a homogenized set of moderation rules across the entire site. I think that is very plausible, but also will further kill what made reddit special, and if we're talking about centralized platforms, facebook dwarfs reddits users, and for the "I don't care about how the site is run" large mass crowd that also does't care about NSFW niches and such, and DOES care mostly about ease of entry and finding communities - I could see facebook groups eating reddits lunch in the masses, while the others move on to places like lemmy.
OT slightly: I've had multiple interactions on lemmy now where I seem to miss communicate something in a way I didn't on reddit or in e-mail listserves. And I'm wondering if it's cultural or ??? Specifically - I tend to quote and comment on the part of a comment I'm replying to that I have something to say about it. The parts I don't quote I (thought) I was implicitly not arguing with or for and at worst would be neutral to I support because I didn't "rebut" in my reply. But instead it often seems to be received like you did of me missing nuance. I tried in my initial reply to point out A) this is a rant (so don't take it that seriously) and I tried to imply B) I'm ranting about this one specific nitpick of the post. Is there some way to do that better? A "signature" I paste in (seems pretentious)? Some formatting change vs quote -> comment / rebut? Thanks.