That's part of the problem with the whole "it's not pedophilia, it's just lolicon" argument. It's not necessarily a dodge (people do fap to fantasies they would never, on any plane of existence, want to actually live out), but it does create ambiguity. Is everyone who enjoys these threads a potential (or god forbid actual) creepy uncle? Probably not. Do these threads have unlimited potential for it? Probably yes.
It's arguably less weird to engage in baby-play, incest play, or ageplay with other adults in real life than it is to coo over belly fat in these threads. The former at least ties the taboo we're enjoying to real live adults, making us confront what we're into and share it with other people of age.
Fuck if I know overall, though. I just know I've liked drawings like this since high school and have no interest in fucking kids. Good test: Read about the Children of God cult sometime. They literally raised hundreds if not thousands of children in mini-societies that treated incest and cross-generational sex as something completely normal and healthy. And their mascot/savior, who they released frequent upbeat sexual stories about, murdered one of the people who screwed him throughout his childhood before capping himself. If their real-life, acting-out-/co/-and-/l/-fantasies actions still strike you as something that could maybe kinda possibly work if done right? You're probably an honest to god pedophile.
Be ready to want to die if you read the Children of God stuff, though. The Story of Davidito is one of the saddest fucking things I've ever read.