I think everybody is different, so there can exist people who are not completely AB, they dont have to go all the way if they dont want to, feelings depend on each person.
For example, I dont consider myself a complete AB, I do wear nappies and suck on a pacifier or bottle and hug my Pikachu doll but only for a sense of security, I would not want to engage in adult baby activities such as being fed or taken care of (with the exception of having changes). My feelings are mostly for the nappies so I am mostly a DL, I would never suck on my pacifier without them as it just doesnt feel right for me, nappies are more important, the pacifier and bottle just add to the experience (and it makes me feel young and safe). My mind is still active though, unlike ABs who's mind acts like a baby, my mind is still aware that I am an adult and I still do what I do in my everyday life.
So I could be an ABDL, just mostly DL, it all depends on what activity you engage in more and since I like nappies more then I am mostly DL, and not a complete baby. But in my opinion what it all comes down to is what you love most, it doesnt matter if your not a complete baby, if you wanna wear nappies but dont want to be treated like a baby then thats fine, be who you want to be, I prefer being mostly DL, so there you have it