Isn't it sort of sick and cruel to buy/imprison animals that have been forced to exist for the purpose of being kept as an accessory? They're cute though
I’m glad you asked! As a tl;dr:
Tarantulas and other reptiles aren’t considered the same type of pets as cats and dogs. You wouldn’t keep your dog in a cage all day because a dog requires exercise, affection and other things. Tarantula needs are extremely low. They just kind of exist. They aren’t pets to cuddle with or be handled (I’ve held mine once, which was that picture when moving him into his terrarium), so they will be more than happy in a terrarium as long as you can recreate the sort of environment it requires (often high humidity and scheduled but rare feedings). It’s actually no different than keeping fish, actually. As long as you have the experience required, they’re doing perfectly well.
Tarantulas aren’t roamers, and most of them live in burrows and spend like 95% of their time just sitting in it. Sunny made his own lil burrow and he loves chilling in there.