Everyone's going to say No, and "just subscribe to the most active one", but if you're a 'Fediverse completionist' and want to ensure that there's not a single thing you miss anywhere at any time, then the answer is Yes.
Correct. Ultimately it's up to each person how much they want to extend themselves into the Fediverse. You really can't follow everything everywhere all the time, so you need to pick what you want your feed to consist of.
I've subscribed to any redundant tech / IT security related communities no matter how many of them there are, because I always want to stay current on any news that could impact the network environment I manage.
On the other hand, I like seeing some memes, but memes@lemmy.ml will absolutely flood your front page if you subscribe to it, so I stick to a few smaller meme subs like starwarsmemes@lemmy.world, risa@startrek.website, and lotrmemes@midwest.social.