The real solution would be a regular, centralised service run by a non-profit.
In the RedditAlternatives sub you can find the most hilarious responses to "I don't understand lemmy, it's way too complicated!". Quickly someone will respond with "It's not complicated at all..." then proceeds to type out a paragraph of instructions and FAQs without a hint of irony.
Like you said, users just want to hit the ground running. They don't care if your using php/asp/vbb/[insert a multitude of framework names here]..decentralized, partially centralized...they just don't want to know.
For the record I do like Lemmy, but I'm a sucker for novel implementations.
I'd set up a social benefit company that's co-owned by workers and contributors. We'll create scoring mechanisms for every action, and for hourly w2 work, etc. Pay out dividends based on your points.
Points would also give you power in town meetings, we'd also create the idea of regions so the fantasy and sci-fi region with the GOT, star wars, star Trek, etc subs could meet and decide on matters affecting their subs.
Each major sub with 10k or more could schedule a one on one with the board, but issues and feedback are always accepted.
Protocol wise the major differences are: we'd centralize auth/login as well as taxonomies like channel names or subreddits, or things like tags. We'd also centralize usernames.
Doesn't matter what server you sign up on, your username is still just username, not username@stupidserver.com, and any channel in the Reddit app namespace could only have unique sub names, so AMA could only be added once, so there's that one topic one major community thing Reddit has going for it.
The rest of my ideas are TBD, though I'd like if Reddits could have need subreddits.