> hes not going to tell you, thats his whole gimmick

Nah, it's so you have no "proof" just how crappy his "workflow" is.

Is it common for uploaders to take subs from other uploaders and make them their own?

AI will be everywhere in the future, better get used to it.
There's a reason why Crunchyroll experiments subtitling with AI.

He already knows the source is lossy, what he doesn't know is that he thinks he can recover these generational loss from lossy format using AI. It's futile because the data/information is already lost/missing. These "attempted" recovery of said data is artificial and pointless even using lossless format like FLAC as the output.

I get your point — data lost to lossy compression is gone, nobody can deny that. But that doesn’t mean remastering or filtering is "bad" or pointless. Anime remasters prove this every year. Take old shows from the 80s/90s: even when the original cels are lost, studios and fans still manage to clean, upscale, and color-correct the video to look far better than the VHS or early TV rips. If "bad source = doomed forever", those Blu-ray restorations wouldn’t exist — yet they do, and they sell because the improvement is obvious.

Also, anime is unique because of its art style. It’s mostly flat colors, strong outlines, and repeating patterns — exactly the kind of material that can be enhanced by filters and AI. Line sharpening, debanding, color stabilization, and AI upscaling don’t "recover" the lost pixels, but they reconstruct them in a way that looks authentic. That’s why things like Anime4K or Waifu2x are widely used: they work specifically because anime isn’t natural footage.

Yeah, exactly — AAC does throw away frequencies permanently, no argument there. But that doesn’t mean there’s nothing you can do with it after the fact. Restoration isn’t about magically pulling the lost frequencies back, it’s about making what’s left sound better. Tools can smooth out the artifacts AAC introduces, balance the mids and lows, and even mask the holes so the track feels cleaner and less compressed.

That’s why studios still remaster older anime audio even when the original masters aren’t available — because even from lossy sources, you can make a version that’s more listenable. The missing data doesn’t come back, but the experience can be improved, and that’s ultimately what matters to viewers.

So yeah, mathematically "gone is gone", but practically speaking, remastering works. If what you’re saying were 100% true, there’d be no difference between a VHS fansub and a Blu-ray remaster — but everyone can see and hear the difference immediately. That’s why dismissing all restoration as "bad" doesn’t hold up.