> I'm curious though, if someone has an ancient/niche architecture, what's the benefit of wanting newer kernels to the point where it'd be a concern for development?
Wanting big fixes (including security fixes, because old machines can still be networked) and feature improvements, just like anyone else?
> I presume that outside of devices and drivers, there's little to no new developments in those architectures.
There's also core/shared features. I could very easily imagine somebody wanting eg. ebpf features to get more performance out of ancient hardware.
> In which case, why don't the users/maintainers of those archs use a pre-6.1 kernel (IIRC when Rust was introduced) and backport what they need?
Because backporting bits and pieces is both hard and especially hard to do reliably without creating more problems.
Wanting big fixes (including security fixes, because old machines can still be networked) and feature improvements, just like anyone else?
> I presume that outside of devices and drivers, there's little to no new developments in those architectures.
There's also core/shared features. I could very easily imagine somebody wanting eg. ebpf features to get more performance out of ancient hardware.
> In which case, why don't the users/maintainers of those archs use a pre-6.1 kernel (IIRC when Rust was introduced) and backport what they need?
Because backporting bits and pieces is both hard and especially hard to do reliably without creating more problems.