One big difference is that with squats and deads, massive amounts of weight are being moved. With abs it’s mainly body weight exercises. I see it working both ways. I’m doing them 3x a week right now and like the results. But I see your results and nice job. Abs are made mostly in the kitchen anyway. Right now I’ve put on 18 pounds since August and just trying to keep the core in reasonable shape while I bulk.
When I am stretching (which you will do when you wisen up and are old) I throw in some good crunches, I do hanging leg raises every few days til I cramp up Abs are flexed and used constantly when training, when I am leaner they look better, when I am FAT they are not as sexy. Do em at least 3x a week mostly to keep everything moving and flexible as possible.
I don't have the best ab workout, I just have the best ab workout for me. As for what I do, 3 sets of 4 reps once a week. This was last year over summer. Currently I look like a pile of smashed dog shit with my winter fluff.