Tether is not going to stop because of this new MiCA rules, now they are investing in another stable coin project called StablR to promote stablecoin adoption in Europe.
Its expected, that they will adjust somehow as EU is too big of a market to lose.
Why does anyone still prefer to use that dangerous pile of junk?
That's a good question, but probably because after so many years of listening about tether being scam and just about to collapse, nothing really happened. And because it managed to remained pegged with USD for the vast majority of its existence (iirc, last big drop they had back in 2018).