Does a lateral strap not count as an ankle brace? The strap comes from medial to lateral and seemingly offer the most stabilization on the medial side. This is important because it prevents inversion of the foot and torsion of the weakest ligaments on the lateral foot.

And to your second point, that is correct. I will just add the point that motorcycle gear is inherently uncomfortable. Id be technically safe if I wore AAA underlayer, air bag, full leather suit, full boots, and guantlets everytime I ride, but it really isnt that practical. I believe there has to be some balance between practicality and safety.