small screws in general are just easy to strip
Hexes are very sturdy. I ride mountain bikes and for some reason brake rotors are secured with Torx while all other screws are hexes. Torx on rotors are usually tightened to 4-6Nm and they are single use 99% of the time. At the same time there are plenty of hexes of the same size which are tightened to 8-10Nm and there are zero issues.
Torx are fucking useless. And don't get me started on tiny Torxes in laptops...
Fasteners are standard from rotor manufacturers. I have no clue what they're made out of. But in 30 years of cycling I've never had a single Torx which would last more than one cycle of screw in screw out.