>>45464615I think it's mostly popular here because it's another monster partner series that's more willing to take risks or maybe because Digimon typically centers around caring for your digimon more than pokemon, probably because it started as a tamagotchi spin off.
For instance in pokemon you just need to reach a certain level to evolve most pokemon in digimon you might have to make sure they don't get ill or make sure that they're not over fed. Even in games that follow the pokemon formula more closely like cyber sleuth there's still a bit of the care management system in the way that most digimon need specific stats to evolve which normally entails feeding them certain foods.
Also the original anime that a lot of us grew up with had some really good episodes that dealt with shit pokemon would never dream of like adoption, divorce, inadequacy complexes, and (most relatably for pokemon fan) autism which I think really spoke to people.