I got a mastodon account when twitter started flaking out, and I've been enjoying it. I would say I never had a twitter account, but for some reason I do. Firefox says I made the account in 2012, but I don't remember why, and I never used it. Might not even work, but I haven't wanted to test it. One less click of support for twitter. I also deleted my reddit account after overwriting all the comments I had access to.
Anyway, I got the mastodon account because I believe in federation, and taking control away from companies. I wanted to see how it worked. Using it, I can interact with reddit type pages, or anything using the activitypub framework. It's a little work, and a little janky, but it can be done, and I expect interoperability to get better with time. A lot of it is incompatible purposes. Mastodon is short form comms, while lemmy is long form. Kbin seems to combine both, but is less developed, and I haven't thoroughly looked into it.
I've met some cool people, and nothing has been recommended to me. If I see it, I signed up for it. No company pushing ads, or promoting users for whatever reason. Might be a little harder if you want to be spoonfed, but the quality is higher, and you get the joy of discovery.