The other thing to consider is how the rest of the market compares: a lot of people have routers which still work but are no longer secure, so this entire field seems right for a legal requirement of, say, a decade support period and/or mandatory recycling.

The key thing to remember is that there’s considerable variability across different peoples’ experience. If you live in a widely spaced suburban house, you probably don’t need to worry about interference the way an apartment dweller does or even someone in a city where the neighbor’s property starts a lot closer. The layout and materials used in your house similarly have a big impact on whether your devices are operating on 5GHz close to a base station or 2.4GHz further away.

Since you have your latency sensitive devices on Ethernet, you probably are fine with an old AP. Cables are definitely better but not everyone has permission or a suitable way to run them (my house built in the 1930s did not include spare conduit).