Are longer teeth more aesthetically appealing? good to save enamel because it gets worn down anyways? bottom front teeth enamel feels more drybrittle

It depends : Teeth should be proportional with the face from the stand point of shape size age male or female. So in some cases with too much wear and collapsed bite , would be more esthetic to make them longer but that would usually involve a full mouth reconstruction since just making some teeth longer would interfere with the whole bite and its impossible. Consult with a dentist or a prosthodontist.

Depends on face: Other facial proportions play a significant role in esthetics of front teeth, the gum tissue , lip line, so it depends. Longer teeth usually look better on a long face. A well-trained dentist can give you some guidelines to look at. The 'golden proportion' is a good start. Always good to save enamel. Bottom teeth may be brittle due to grinding teeth, diet, poor habits.