I’m a bit less extreme about it than many here. But, in short, back when Reddit made sweeping API changes it immediately gave me ‘the ick’ and so I sought less centralised platforms. Lemmy is the closest thing I’ve found to people just hosting their own message boards like back in the early internet.
I’m a big fan of decentralized platforms and I love the concept of ActivityPub.
That said, I still use Reddit and have recently started to really enjoy BlueSky, so I’m not militantly against the corporate platforms or anything.
Finally, I just like the natural selection things like Lemmy and Mastodon have for those who are naturally more techy and nerdy.
Personally, I think it’s great. It’s a smaller community than HN and the registration requirements, whilst not a perfect solution, do create a litmus test and ultimately creates an envrionment of mostly high quality posting.
To get in, you need to be invited in by an existing user. If you don’t know anybody, you can hang around on their IRC channel and once you’re familiar, somebody may be willing to invite you.