I wouldn’t call it an anime trope, given that it’s not, to my knowledge, a thing that typically happens in anime. It could conceivably happen in an anime, but if it did I don’t think any anime fan would point to it and say, “ah, a classic example of the mountain-cleaving trope!”
Regardless, I did pick it as my example specifically because it was reminiscent of the kind of feats that might be treated as achievable by nonmagical folk in anime. To illustrate that, yes, in a fictional work, things that aren’t possible in real life can be possible without “magic” being the explanation. I am not literally asking for a “split mountain” feature on 20th level fighters, I’m using an illustrative example to make a point about how not everything beyond the mundane need necessary be magical.