people are literally just reverse engineering these applications by having the LLM decompile it and observe what it does
Have you seen the creators of this particular project claim anywhere that they decompiled anything? I've seen several commenters claiming that but I think they're incorrectly assuming that that's what they did.
For one thing, decompiling and recompiling Adobe or Microsoft code would surely be viewed as copyright infringement if there isn't a clearly-documented "cleanrooming" process in the middle (having an LLM write a spec (in English) from the decompiled code, and having another session without access to the copyrighted code write new code from that spec - a fun LARP many people are doing lately).
But also, if they were actually doing that then I'd expect more feature parity than I've seen in the few youtube videos I've skimmed through showing these apps. I'm too lazy to find the link now but I watched one comparing PhotoCraft to Photoshop, and one example was that PhotoCraft's Levels diagram is very primitive in comparison to Adobe's (or to GIMP's for that matter).
I did something similar recently where I had an LLM figure out the proprietary format for the way my Nikon camera stores RAW files. There’s currently no open source implementation for it, and now I can read them using my own library. So, something that used to be a herculean effort before, is something you can now do in a few days using an LLM.
Congratulations, that's awesome (and I don't doubt it). But implementing a RAW format is a lot easier than re-implementing all of the Photoshop features which are required to be able to say (honestly, a least) "this has .PSD file format compatibility" without a long list of caveats.
I am using his PhotoCraft and LightCraft, and they work fine for what I need. I can process my photos using completely open source tools now that have a UX I’m used to.
I am curious how much you've actually used it. Eg, can you confirm what I saw on youtube showing the Levels adjustment dialog lacking most of the features found in Photoshop's and GIMP's? (Is that still the case in the current version?)
And have you noticed it having compatibility with (or at least some support for) any modern PSD file format features which GIMP lacks?
You’re saying this as if NPM ecosystem didn’t exist before LLMs.

yes there was a lot of crap before 😭 but don't you agree it's 1000x worse now?
You look at the number of stars a project has, how long it’s been developed, how many users it has, and so on. This gives you an idea of whether it has legs or not.
This project has a lot of stars but only because it just got a ton of clickbait press grossly exaggerating its completeness. I assume the vast majority of the stars are from people who have not tried running it. How long it's been developed is... two weeks, as of today. How many users? It's far too soon to say.
I’ll certainly trade having to rely on proprietary software for the problem of having too many open source options.
I agree with you here! But I'm assuming (perhaps incorrectly) that this particular one is not likely to ever become a particularly good option.