Yeah, you need at least to do a jump back from the edge. I think that's even in the Croft Manor tutorial tbh. It's very open about it being tile based.
I didn't even try "modern controls". I know where I am with the tank controls.
I highly doubt the intent was to always approach ledges, then walk to the edge, then step back, then run forward, EVERY single time you need to make a jump. It breaks the flow of exploration.
Theoretically, you just need enough space. But the game's coding is incredibly murky about how much space that is. I've failed jumps after running forward from the back edge of a block, just because I had landed from somewhere else, and did not then perfectly measure out one full jump-back. Ultimately, it causes plenty of annoyance and makes the controls inconsistent. If you want to read it as "You didn't correctly backstep at every single jump" then it just means the game is boring.
I mean, it's from 1996. 3D games were in their infancy.
It's a very methodical and laborious game about checking every last corner and crevice for a way forward, and it's really not a game that concerns itself with flowing gameplay. Everything is awkward. It all feels very deliberate, from the block based layout to the walk button that takes you right the edge of them.
There's a few bits where you need to keep running and jumping (the timed flame puzzle for example) and those can be iffy, but there's not many. It's a game of its time, and they've preserved it all. I'm surprised how well it still holds up if anything, considering the gameplay is left as intact as I remember it.