How many accounts should I have for the fediverse?

So far I use: Matrix, Friendica, Lemmy, PieFed. I also follow 1 or 2 persons on Mastodon, using Friendica.

I want to try vutuv now. Maybe in the future some more services.

Now I wonder if I should really register a new account for each service. May I ask for your advice? What do you recommend?