my entire interest in the meta vr glasses is on-device eye tracking; I think that interface concept has been under-explored.
Hand-tracking is a terrible idea without micro gestures and eye tracking - because your arms tire very quickly and pointing at things is very inaccurate. There's a reason why brushes are more popular than finger painting)
Of course - we've already invented the optimum solution which is tracked 6dof controllers - but someone decided they aren't ever going to be mainstream so here we are...