"Home Wireless Networking is still pretty much an unsolved problem for average consumers."

What do you mean? Most consumers have a wireless router, and that works for their needs.

If you live in anything other than an apartment, your wifi connection drops considerably once a few walls and a floor are in the way. Mesh networks solve this by repeating the signal halfway to your hard-to-reach devices, although it must be done in an intelligent way if you want seamless band switching and its performance might be greatly improved with wifi 7's sensing capabilities.

My router is in the basement. Reception is great throughout the house, including the second floor, and even decent out in the garage or on the deck. Similar setup and results for my in-laws who have a massive house (3000-3500 sqft).

Many houses and places of business have walls or floors made with thicker material that block/hinder the waves - things like solid wood floors, brick walls or concrete walls can do a number on even 2.4ghz signals.

The in-laws have hardwood floors on both levels. I haven't seen internal masonry walls in most places.

Even if that is a concern, I don't see sensing as being a benefit.

Yup - and wiring up a second access point for the upper floors gets rid of all the issues with mesh networks, especially ones from vendors that don't provide dedicated radios to mesh over.

If you don't have the expertise to run ethernet cable yourself, just find local companies that install alarms - they have lots of ways to run and hide cables; it's their job after all!