Trying to solve wifi dead spots across my then house. It didn’t have wired conduits, so no ethernet between floors. Went through a series of range-extenders, multiple routers, everything from cheapo no-names, to TP-Links, Netgears, and Apple Airports. All sucked. Terrible reception in all the places that people hung out.

Then mesh routers showed up. Got a 3-pack and never looked back.

Edit: runner-up was an HP Inkjet printer. Every time someone needed a color print, one color ink was either out or dried out.