>>56178171They steal from young trainers to get access to pokemon that have barely bonded and to 'break in' new recruits.
Rare pokemon are used for breeding/selling them to collectors and other such people.
Most rocket money making is from exploiting pokemon/established systems, corruption with daycare centres -eggs go missing-, more schemes like Slowpoke tails.
Stealing trained/experienced pokemon is not worth the time invested. They will resist and unless you go grimdark with pillory breeding stalls then they're not going to breed. Selling them is an option but there's not many buyers who would pay enough to make it worth the trouble as a sustained business instead of an occasional thing.
Team Rocket is like a budget mafia