The brake shoes on a vehicle are made to last at least 35,000 miles before they wear down and need replaced.
However your driving also factors into the lifespan of brake shoes on a vehicle and the more stop and go driving you do or the more stopping you do with the brakes the more often the brake shoes will wear out and need replaced.
When you do more highway driving the brake shoes will last longer than when you do a lot of city driving with stop and go traffic such as stopping at a lot of traffic lights.
Also if you do a lot of towing of trailers with heavy loads then it takes more to stop that trailer with the load on it so your brake shoes will wear out more often.
But you should get at least 35,000 miles or even sometimes more miles out of a good set of brake shoes.
The brake shoes on my truck have 25,000 miles on them and they are still pretty good but I believe in about 10,000 miles more that they will need replaced.
I will be replacing the brake shoes on my truck by then anyway because I do them myself and they are pretty cheap to buy.