The truth is; a lot of us feel like we need more internet accounts about as much as we need genital warts.

You are confusing decentralized and fragmented (or self hosted). The promise of fragmented software (like Lemmy) is that there are many instances but an agreed upon protocol. You create one account on one site and then use it to pull and push data to any other site that uses the same communication protocol. Like you and I for example. You created an account on lemmy.zip, I created one on lemmy.world, and we are both discussing a post created by a user on lemmy.nocturnal.garden (an instance I have never heard of).