If we are speaking current distributions, Python 3.9 actively refuses to install on Windows 7 and dropped the relevant compatibility code (though I think 3.8 might have had problems installing on it as well).
I don’t think this is a fault that you can blame the Python developers for, necessarily (indeed the end of support is exactly the reason given by the Python developers well in advance), but I certainly do think that it is a plausible scenario where you might end up being forced to use an obsolete version of Python as a result of the decision.
I also think that a curt “EOL operating system” dismissal has a problem that, taken to the extreme, it says that every software author would be justified in following the support schedule of any dependency, however inane that schedule is,—and there’s nothing in that dismissal that would prevenr it being taken to such an extreme.
That is not to say that running Windows 7 now is a particularly smart decision, no patches means no patches after all, no matter the marketing motivation behind that decision. I’m not even sure I’d call this particular part of Microsoft’s support schedule unreasonable. I am failing to find a legal, generally available, and supported Microsoft operating system I’d be willing to run, so one of those parts would have to be given up; but that is not the point.
The point is that there should not be a blank presumption that a vendor declaring EOL on anything at any moment is automatically reasonable and that it is right and proper to follow them. It certainly is simpler to offload that decision to them, but some sort of underlying sanity measure the result could be checked against ought to exist, and the parent comment (not that their stance is unique) is failing to provide any.
yt-dlp currently has no plans to drop support for Python 3.6, which became EOL a month ago. And Python 3.8 will be supported until October 2024.
On Linux (at least a regular x86/x86_64 machine, not sure about other architectures), you can generally easily install an up to date Python version with pyenv.
My personal machine is on Arch Linux (which recently moved to 3.10 without any major problems) and I know about yt-dlp, so I’m not having any particular problems here :) It’s just that the great-grandparent asked for plausible scenarios for using obsolete Python, and Windows 7 support immediately came to mind.