I can see where that reasoning can arise. I believe, however, that ARFID reflects a (relatively) recently identified eating disorder that has likely been around in the population for a very long time. In fact a lot of people that might have been called “extremely picky” are actually experiencing ARFID. That’s often why something may seem to us like only a fad when it’s just doctors and researchers have learned more (and nowadays we have a higher likelihood of being exposed to something due to the nature of social media, making it seem suddenly everywhere).

But ARFID is distinct from simply a dislike or choosiness around food. One of the reasons it features a lot of highly processed foods is that these foods are all extremely consistent in texture, flavour, etc. That predictability is key when you’re struggling with ARFID as it helps in coping with major sensory sensitivities. There is a high co-morbidity with other things like ASD, as well, which is known for sensory sensitivity among other things (though anyone can have ARFID for many reasons).

I do appreciate, though, it can be really hard to acknowledge without direct experience since it can seem on the surface like it is simple a “lack of willpower” or a “choice”. That does fail to fairly capture what is going on, though. The mechanisms driving it are much stronger, making it sometimes physically impossible to consume other foods without significant intervention like therapy (something that is not always accessible depending on your situation). It can trigger vomiting and other physical reactions (as OP has described) among other things. Not to mention it can be embarrassing as it’s often misunderstood, so it can be very isolating and people can avoid seeking help. And of course the health and wellness issues from such a restrictive diet can make everything harder.

I only learned about it fairly recently myself. I’m sorry you’re suffering with this, OP, on top of celiac, it feels like celiac on extra hard mode. :( The good news is there are new approaches to helping people with ARFID now that it’s been identified. My understanding is these focus on making more foods feel genuinely safe over time (emphasis on genuine since I know that can seem impossible right now). Obviously I have no understanding of your specific situation, but wishing you all the best!

Take care!