I mean, you're right, it kind of is provoking an "immune" response 🤷🏻‍♂️. Several UIs already add badges to new accounts since trolls spinning up new accounts to ban-evade is an ongoing problem.

I maintain a Lemmy UI, and I'm now adding a feature to let people hide new accounts; they can specify a minimum age and only accounts older than that will be shown in communities they're not a moderator of.

Of the problems lemmy currently has, people making throw away accounts isn't really high up on my list of cancer level problems.

Lemmy.world getting so big it can take days/weeks for content to federate is a huge issue, many communities on lemmy.world simply don't show up on my instance, or my posts don't show up on their instances for DAYS!

Small communities need better moderation tools (in community posting requirements, account age, karma, only voting if your an active poster in the community)... right now niche communities get stomped pretty hard by drive by hate-engagement.

Searching though a specific person's posts (like finding a post i made myself)

people able to kill entire threads by deleting the post, all the contributions of the community disappear, discouraging engagement.