For a couple years now, we already have had private servers for LBP, specifically for PS3, Vita, PSP and PC. No PS4/PS5 though which was what LBPOnline was gonna offer.
Beacon (on the left) is the more popular server (35k users), but Vita is down rn and never has had PSP.
Bonsai (on the right) is much less popular, but with great features such as being able to directly load levels from the Dry Archive (which is the archive of 10 million+ levels that LBP had) and Vita/PSP support, it's currently in read-only mode though but that is apparently temporary.
These servers are great, and even have team picks containing only new levels created by the community. You can also join friends (granted, Dive-In doesn't work for security reasons, you have to give a specific key to friends for them to join you.)
You will need your console hacked, however I can say that it is not that hard. I don't even know many who DONT have their consoles hacked. It's quick easy and usually safe for PS3/Vita and even PSP. I know some people can get worried about their PSN being banned, but not only has there been no case of it in the years long lifespan of the servers (from what I know), you can just use an alt or use a PC if you really want to be safe. If you have a good enough PC you can use RPCS3 (it doesn't have to be the best of the best, something mid range is fine, just know lag can happen in stressful levels without a good CPU, but RPCS3 is constantly improving) turning off MLAA helps for performance. Do note RPCS3 and PS3 crossplay is impossible.
Patching the games is simple too (https://www.lbpunion.com/beacon/#patch or https://docs.lbpbonsai.com/ps3.html)
If you want to use beacon but want levels from the archive, there are reuploads, but also this (https://maticzpl.xyz/lbpfind) to quickly download and plop the levels from the archive into your game.
This post is to spread awareness to these, as some people think LBPOnline was the first time the servers have come up ever (I know some of you only have a PS4/PS5, this post is dedicated to those who just weren't aware.)