I used them all the time when I worked at dealer
often, say, front axle had issues, I'd drop the axle out of the tractor. Of course the shop and dealer was small (tiny) and everything had to be ordered, very few parts in stock. When I had to do an axle repair, rebuild, whatever, I'd pull the axle out, then use the loader to lift the nose of the tractor, hold it, and then drive it out using the brakes to steer. Easy. Frees up a lot of space-which as I mentioned, was very important in a tiny shop barely big enough for one large tractor (>100hp).
Or if one had fouled up steering, drive it into and out of the shop using the brakes to steer.
On mine at home (MF 1145) I use the brakes on it just the same, to steer when the wheels won't, let's say I'm moving dirt or gravel or clearing the driveway when it snows outside. Steer, or at least assist the steering, with the brakes. Also, when I got it stuck last year, one wheel was in the mud, other had traction. Mash the brake that was in the mud, pulls it right out.