HMs would be fine if they were reworked so that a variety of moves could be categorized as field moves. Cut, Slash, Fury Swipes, False Swipe, Night Slash, etc. should all be able to cut trees. Rock Smash, Brick Break, Karate Chop, Headbutt, Horn Drill, Seismic Toss, etc. should all be able to smash rocks. Any Water Pokemon of a suitable size should be able to traverse water, waterfalls, and whirlpools. Any Flying Pokemon of a suitable size should be able to fly. Restricting it to specific moves that you can't delete at any time makes the entire idea unnecessarily intrusive.
