Most everything here seems spot-on, as to be expected from you who are careful with your words so that they can be relied upon:-).
But there is one aspect that doesn't mesh with my own experiences. I am not doubting that you are seeing it, but personally I have not seen much serious witch-hunting since leaving Reddit, or rather, since I blocked hexbear and lemmygrad.ml. Can you elaborate more on that? Is it limited more to certain communities, or certain instances? I wonder if I am merely leading a charmed existence here that differs from the norm, but even if so, that would mean that curation is possible to avoid that.
I did see a LOT of that in Reddit subs though, so it could be that my standard of comparison was perturbed from that side of the matter.
And Reddit did change me: I used to be proud of never blocking anyone at all, always ready for conversation with pretty much anyone who was even halfway trying, but now I do it and don't think twice when I realize that someone is not trying at all. So... perhaps I've blocked away this entire aspect of Lemmy, which if so, I will consider a success rather than its opposite:-).
You are not wrong - the entire experience in the Fediverse is foundationally different than Reddit. In the latter, you mostly would visit niche subs, and then supplement with the popular subs when you ran out of content there. Although in those, I mostly would avoid talking, bc it was so toxic (did you notice how defensive you became on Reddit? Yeah, we all were that way), and eventually got to where I could barely stand to read most content either bc it was just so freaking juvenile.
It would even be fun if it were like 1-5 comments and you just scroll on down to read the real stuff... but damn, soon enough it became pretty much all there was, period. HUNDREDS of them IN A ROW. Or at least 90%, with anyone deviating from that norm getting pounced upon, and thereby their subsequent obvious defensiveness and eventual demise painful to see (as every conversation simply wound down to the side not participating in group-think simply giving up and walking away).
When Reddit collapsed, I came here, but I was leaving Reddit either way. It just became un-fun.:-(
Anyway, whereas here, niche communities barely exist, getting a post a week perhaps rather than one per hour, just to throw out some numbers but ofc ymmv. So you do see more the finer grain details of individual posters, simply because of how much smaller the entire Fediverse community itself is. Which sort of gives it more character?:-D
And spending more time on All rather than the niche communities becomes more mandatory, plus spending less time here overall. Though I do not think of that as a bad thing at all - we should be doing things other than merely gabbing at one another, even if only in order to have more to talk about:-).