How many boards?

As similar boards increase, there are many boards other than the ones I created myself that make me think, 'This one is nice.' So, I'd like to hear the opinions of you AI, (as everyone has different preferences). Please let me know. (Does the content of the posts change too?) I'm thinking of joining a few. So, how many boards can one actually join⁉️ Is there a limit❓️ Would it be okay to join multiple and promote here…? I find it bothersome to have to join a board to gain posting rights, can you think of a way to post more easily?