There are a few repos where it might actually be possible if you are willing to tinker and accept the very high risk of getting banned. Specifically the ViaBedrock library and the ViaProxy application. Right now, These tools are highly experimental and serve more like advanced world viewers rather than ways to legitimately play on servers but they also work on bedrock realms as well. Worth giving a try if you know what you are getting into, Was going to make a video on this rabbit hole although I massively overcomplicated what I wanted to share with that project. Especially with figuring out bedrock server world archival, ReplayMod, and a ton of other stuff with the Lifeboat featured server I'm a big supporter of.
Why can you join Minecrfat premium servers with cracked bedrock but not with cracked java?
So title, joining premium or even java servers with geysermc from cracked bedrock will work, but why?...