How to choose MTB bike tyre: hookless, tubular or clincher?
You should use the tyres that fit the rims on your bike. If you were a professional you'd use whatever your sponsor told you to, so that's a bit of a side issue.

Tubulars are back in the MTB world, but they're still rare and it's unlikely your bike has them. I suggest not buying a tubular wheelset, let your sponsors do that when they decide it's a good idea.

Hookless rims have some advantages but not to the point where I would throw away hooked rims to buy them. That assumes you're running tubeless, the advantages of a hookless composite rim with tubed tyres are pretty imaginary.