It should actually say VERY large house since this is one of the larger more powerful devices on the market as of now. I would say easily handle 3,000+ without issue. Some quick study of wi-fi signal range capabilities on google will point out some wavelengths are far faster than others but unfortunately they have a harder time with obstructions than the slower bandwidth capabilities of older slower rated versions. A perfect example of this is that 5G can sometimes be considerably slower than 2.4G for distant locations with more obstructions.The biggest thing to understand is the varying wavelengths and wi-fi spectrum's ability to mitigate the structures walls, doors, wall ducts, plumbing, wiring and other physical signal obstructions. Every house is obviously different in layout and the router location and mounting position alone can have a very large impact on dead or weakened zones. Centralized higher mount locations are usually almost always best to equalize signal strength throughout the entire structure.
This particular unit is on sale right now and IMO, is much more appealing because of the current -$100 off pricing. And although there are other routers that can best it's peak speeds on occasion, and especially in certain less congested environments, it's ability to handle busy "smart device" and heavy streaming households are far above previous gen routers because of the newest OFDMA features. Whenever you purchase and whatever you spend though, early adopters always pay a premium to be ahead of the curve. Hope that helps.