I did not grow up with Digimon in that I had just graduated college when it started airing, but it was one of the last series I watched as a Saturday morning cartoon. People who haven’t seen it tend to dismiss it as a Pokemon knock-off, for featuring young children with monster buddies, but it did something that Pokemon did not. It allowed its protagonists to mature and grow up.
Digimon had always maintained in-universe that no matter how old you were, even if you became an adult, your partner digimon would always be there for you. Intelligent and able to speak, partner digimon are a pint-sized buddy that can be temporarily supercharged to grow into more powerful versions of themselves. No matter how badly their human screws up (and some of them do), the digimon are loyal for life.