The answer to "Why doesn't my music sound as good as I wanted?" isn't going to be "CD's 44.1kHz and 16-bit PCM isn't enough". It might be "This cable has been chewed by a dog" or "These speakers you got with a cheap MIDI system in your student dorm are garbage" or even "the earbuds you're wearing don't fit properly" but it won't be the 44.1kHz 16-bit PCM.
Likewise, it is plausible that Git is done technology-wise. That doesn't mean there won't be refirements to how it's used, recommended branching strategies, auto-complete, or even some low-level stuff like fixing the hash algorithm - but the core technology is done.
Yeah, try telling this to a fan of 1960s or 1970s rock. You'll get an earful about rich guitars and fat synths, which only a 100% analog, tube-amp process from studio to ear is capable of replicating.
And anyone with a basic understanding of electronics should laugh in the faces of these people. The idea that a signal can be carried on a wire or recorded on tape but can not be replicated digitally is absolute nonsense.
If someone wants to claim that their preferred format captures higher frequencies than 44.1kHz sampling allows for, that's at least plausible, but that can be solved by using higher sampling rates like 96 or 192 kHz. At that point you've exceeded the capabilities of all mainstream analog storage media.
If they are looking for specific effects created when pushing the limits of analog hardware, like the "crunch" of a tube amp, that's fine too, but they need to acknowledge that they're treating the amp as an instrument in that case and its output can still be recorded digitally just fine.
Software development has seen massive improvements in the past 20 years. I see no reason why that would stop now.