For most US residences, there is at most 1 wired broadband provider to the house (coaxial cable), and they provide an unspecified anemic upload bandwidth.
Many of us don't have a choice of different providers. And while I agree that WiFi in particular may not be as good as a wired connection, many people also don't have an Ethernet jack near where they work at home. (I do personally next to where I take my calls.)
but in general, yes, I agree, I have had problems with network connectivity in my WFH setup that are very difficult to do something about, and which are very frustrating to all involved, it is a problem.
I've extended WiFi with a power line adapter. It works but I had to try a few plug combinations for it to work. I know with X10 (yes, long time ago), you could have issues spanning your electrical box from (maybe?) one side to the other.
The instructions that came with the one I got say that it should be on the same circuit or whatever. I am pretty sure mine is not. It works well anyway. Which surprised me, I honestly didn't have high hopes for it, but it has made my zoom calls more reliable vs wifi in my office location.