I thought the manga was always better until I read Chainsaw Man both ways in one weekend
Three weeks ago I binged all of Chainsaw Man part 1 in two days, then went back and watched the anime with my roommate who only watches shows. Around episode 8 the big fight hit way harder for him than it did for me in the manga, and I sat there kind of annoyed because I always assumed the page version wins by default. The sound design and the voice on Denji made me feel stuff the panels never did, and I honestly think the anime does the early chapters better. So what's the actual rule here, is it just whichever one you saw first, or are there shows that really do beat the source?
That line about the sound design and voice making you feel stuff the panels never did is the real answer here, because animation adds tools manga just doesn't have. Once you factor in music and actual voices, it stops being a fair fight and starts being about which version uses its own tools better.