Something tells me that a kernel from 1995 would run on lower-end hardware than a 2023 kernel with "speed improvements" (and an unmentioned million added features)
Sure, it might. But that doesn't mean things like schedulers or I/O handling haven't improved and got better in terms of latency or at handling various workloads.
Other things that may not be noticeable to most people but matter to others may also have improved, such as audio latency; I don't know how e.g. Pipewire or PulseAudio compares to plain ALSA in terms of that, but at least plain ALSA apparently wasn't enough for audio work back then because there was Jack, and I'm also under the impression that latency and responsivity in general have improved a lot on the kernel level as well, and not just in terms of audio.
Open source graphics drivers have also improved a lot over the years. Perhaps the entire graphics stack has, or perhaps overhauls of the stack have facilitated some of the improvements in the drivers themselves, but I don't have enough expertise to judge that.
Improvements (or degradation) in performance are rarely something that happens evenly across the board.
Do you mean what counts as lower-end hardware in 2023?
In that case, I doubt it. You probably couldn't even use all your RAM. Linux back then also supported only a single processor (if it boots at all): symmetric multiprocessing support was added in 1996.
