When will they learn?
Household mains electrical wiring is not a network cable!
It's unshielded, unbalanced, acts like a leaky feeder and pollutes the local HF and (now) VHF radio spectrum with broad-band digital noise.
I know you've heard all this before from us radio geeks, but it needs re-itterating.
Companies should invest more on developing faster WiFi instead of this crap.