Because it’s a bandaid on an arterial bleed of a problem and has its own host of issues (anoxia once the algae blooms die off being one of the big ones, aside from the cost of actually doing it on a global scale). Lots of discussion around whether it makes sense to do, but really for the effort to do it, and the unintended effects on the environment, it would probably be better and cheaper to just reduce GHG emissions.
Depends on how your house is set up and whether you have a clear shot between the router and the room through the walls/ceiling/basement. I just moved my router to the basement and ran cat6 to an AP on the second floor for better connection in my office. Took me a day to figure out after the route I figured I could go didn’t pan out and I had to do a big loop instead of tearing through drywall… completely dependant on your layout!
https://snapcraft.io/wormhole if you’re both using Linux would be a good option potentially.
Creating an entirely new industry “for the economy” is the reason this is even being contemplated. If you care more about the economy than the planet you live on and the people you share it with, then maybe that makes sense.