I guess it could help with stopping bots from bombing comments with upvotes and such, but it's the only platform I've ever seen that behaves like this.
I created an account a while ago to show appreciation to an answer I found helpful, but I couldn't upvote it. It just feels weird.
It's precisely because we're so different from other platforms that we do this.
Stack Exchange is essentially a peer-reviewed Q&A site. We're a bit like if Wikipedia articles had voting and people competed to create the best article, and we have some standards and philosophies that guide what makes a good answer.
Newcomers however regularly mistake this place for a linear discussion board, using replies to chat with authors of other answers and then learning we don't work that way by surprise when we downvote and remove that post.
We want you to have a little bit of familiarity with how our site works before you begin interacting with the quality measures. We want you to provide a minimal demonstration that you know what a good question or a good answer looks like by posting one, and then you'll be allowed to vote on other peoples' questions and answers. We want you understanding you're meant to vote like this is Wikipedia and not like it's Reddit. We consider it a minimal hurdle, and there's a series of hurdles like that which aim to pace your familiarity with the system and your access to modify it side by side.
It also protects from vote manipulation pretty well. It's difficult to set up several new accounts to upvote your own posts without a lot of work and leaving a significant incriminating paper trail this way.
