I don't know the specifics. He seems to be making a lot of the tokens/maps we use but I think it's being done with an AI art generator, and as I don't use those things I have no idea how much time it would take.
This seems more in line with what I'd expect in terms of prep. But I haven't made any encounters for this game, and back when I still ran DnD my DM friends seemed to do a lot more prep than I ever did so I wasn't sure.
I agree running combat can be a pain, there's a lot to keep track of. Although for me a lot of the more taxing bits come from my group being uh...not well suited for Draw Steel.