[Fuzzard]

> I understand the idea, but: wouldn't it be better for addons to support the Python version Kodi supports for that particular version?
> but as long as Kodi supports 3.6, I think the addons should also support 3.6

unfortunately, the things cannot always work that way

when you develop and you need to add support to new technologies you have two possibilities,
keep legacy dependecies/code and continue to have problems until everything breaks down,
or switch to new dependencies with the possible side effect of cutting off users with older versions of python

limit addons to always ensure compatibility with older python versions is not always feasible or a good choice,
this depends on the complexity of addon source code and what needs are required in some specific contexts

however this is also news to me that python 3.6 is no longer fully supported by some dependencies
it is possible that this premature choice (made by those who develop those dependencies) is because python 3.6 will be discontinued at the end of this year

Python3 is a moving target. The cpython Devs do not ensure complete backwards compat, and they are actively deprecating and removing features/modules in their point releases.
This really has nothing to do with Kodi, it's how python is being developed.
We actively made sure python 3.6 can be used as at the time of release, the lts version of Ubuntu included 3.6. we aim to have the 2 latest versions of Ubuntu lts supported (with whatever default system libs it ships with), but this still requires python Devs to accommodate any differences in the python language across cpython versions

As for the contextvars usage, it's just it was only brought into python3 with 3.7. so I guess add-on Devs either need to have a try block to fallback to some other codepath that doesn't use it, or you will need to say to Linux users your add-on requires python3.7+.

Again, this isn't an issue Team Kodi can solve sorry.