Yes, you have to create an account on every instance that exists and always use that account to interact with that instance.
If you keep a central account, one day you will anger the wrong person and they will blacklist you off the entire fediverse, losing all relationships and history to overcome ostracisation.
I even consider making a new account per instance per month. Maybe the process could be automated too.
You actually better off running your own instance that way you don’t have to worry about getting delisted but that’s not exactly easy.
For those of us non-techies, that’s altogether a daunting prospect!
My background is play therapy with children, and although I did well at the start of the internet: I made my own website and got my head round HTML, then I was doing OK with CSS, then it all raced ahead of me and now it all just looks like magic!
I made an account on feddit.de and I’m not even German (learning to be, though)
Ah I’ve just been subscribing to the communities I want and changing my homepage to view them, I would not be able to manage switching accounts all the time 🙃
That’s a better option! I may just abandon one of the two at some point.