I agree that it's being touted as a panacea and The One Cause. But I think that you can do all those things and still have life suck. For instance, Crohn's and celiac both look similar to the untrained eye. You have digestive trouble. And some generic "just eat healthy" advice won't have worked properly. Literally cutting out gluten would instantly work wonders for celiac, not "less bread, less meat". Literally just "no bread from sources with gluten". So, we just go through and find causes and more precisely intervene.

And the worst thing is that someone would have gotten a bit better with celiac's if they eat less bread, but the problem will have been unsolved. Way better to identify precisely and they can do all these other things and just avoid bread with gluten and can enjoy the occasional matcha mochi waffle.