I honestly do not mind it one but. I quite like the interface. It’s minimal but there are some bugs to it which is to be expected. I really do like the overall design of it though. There isn’t too much going on. It’s like old Reddit which I am a big fan of
An account on an instance is like an email address - if you have a @gmail.com email and a @yahoo.com email, you can interact with people from both. The spam filtering might be slightly different (different instances have a variety of ways they get configured), but both generally get the same job done.
There are reasons you might want multiple to separate things, or you can abandon ones you don’t need and just pick one to stick with!