>>507015121. Humans have no way to survive getting killed by magical animals who can shoot nukes UNLESS they trap them in balls and tame them. It is a survival thing. Gotta do what you need to do.
2. Humans taming Pokemon ensures that they stay on top of food chain. It is to establish dominance, which leads to further technological advancements and discoveries.
3. Pokemon battling is a sport, like boxing and MMA. There are rules and restrictions. It is also mainstream entertainment. Pokemon don't have it all that bad. The ones on top are essentially superstars.
4. Battling benefits Pokemon. They level up easier, they unlock more evolutions easier, they get more mating partners, they have access to more health and medical leisures. Some might get abusive trainers but most get trainers that take good care of them. They get good food regularly, get to live in comfortable houses and some even get to travel the world.
5. Living in the wild is the worst because Pokemon constantly fight each other and the wild battles aren't regulated. Pokemon are literally killing each other without orders from a human. So why not do it under rules and restrictions so you still get to fight but won't die.