It's definitely better to do that, but how are they going to scam new users that way?

Most of these kinds of websites won't just straight up close down after they scammed some of their users, they just keep going and refuse closing down completely until no one registers and deposit anything to their website anymore.

My guess is they will keep operating for a few more months at least, and after they closed down their website they most probably create another website and pull the same thing there and rinse and repeat until this whole thing still works.