I went through a set of brake pads - Shimano L02A or similar - after somewhere between 2000-3000 miles on my gravel bike. A lot of that braking was on dusty, dry descents which I would expect to contribute to pad wear. Apparently the newer version of those pads are supposed to wear better, but I don't have data to verify that.
On my cargo e-bike I'm going through pads after about 800 miles, or at least that seems to be when I should replace them. I waited too long to replace the last pair - 900 miles, I think - and had worn away part of the spring. That's a 60lb bike and I'm usually hauling kids, adding an extra 50-150lbs. The bike came with metallic pads, and I replaced them with semi-metallic. I got the same mileage out of both and couldn't tell the difference when braking. I'll be replacing them again soon and have a set of resin pads this time.