the fediverse is designed to guard against the same kind of enshitification that reddit went into by keeping the same discourse alive everywhere regardless whether you use mastodon or lemmy or any other social media platform.

social media tribalism guarantees eventual enshitification of some kind, so keeping your options open makes sense should you ever decide to set sail on the fediverse sea after the people on your platform island have burned it all down due to the local culture war they insisted on fighting until its pointless end.

i've been switching from one social media platform to another since the 1990's because of enshitification and that's taught me that the platforms with investors behind it enshitify the in the worse ways possible (eg reddit, facebook, bluesky, etc.). so i think that the fediverse has the biggest and likeliest chance to survive all enshitification because of how it's designed to keep the discourse alive no matter how many power tripping mods or majority conversation shaping admins there are. (at least for now).

Only the other way around. You can read and post to Lemmy from Mastodon, but you cannot follow Mastodon content from Lemmy.

I'm not sure about all the same content, but you can see at least some Mastadon content and comments on Lemmy and vice versa. You'll recognize them as they use a lot of #tags and will @ the user they are replying to, which have little use on Lemmy.

You could try creating an account on kbin/mbin instead of lemmy, my understanding is that that gives you the "threadiverse" and the microblogging fediverse on one platform, though I have not tried it yet.

On Lemmy you can only follow communities, not individuals.

In the future, please note rule #3 of the !asklemmy@lemmy.ml community: “Not regarding using or support for Lemmy.”