Recently, I've wanted to start developing my nation's military. I'd like to do it completely from scratch, and I'd like to draw a lot of it, including soldiers, guns, planes, you name it. I see a lot of storefronts with images like this (not mine, belongs to Mikaylski & Aviram Armaments)
Looks pretty good, right? There's a ton of similar art on here, but I can't seem to find a good platform to draw on. I'm usually on a MacBook Air, and I've tried GIMP, which for some reason is really laggy. I've had success with it in the past, drawing my nation's maps, but it doesn't do good with precise measurements, which I'd need if I'm drawing a vehicle or gun. I could probably use it for a soldier or something else more vague, but like I said, I don't enjoy using it due to poor performance.
What I'd like is a program where I can make all sorts of art, with precise measurements so it doesn't look sloppy. Keep in mind, it would have to be compatible with MacOS. I appreciate any help y'all give!
Moderators, feel free to move this, I'm not sure if it's in the right place.