> Often the newer ones have large amounts of "waste space" where hallways are larger, entryways are larger, rooms of course are larger.

That house seems to have been built in 1971.

In contrast, here is a brand new home in the same city that is only 1200 sqft.

https://www.zillow.com/homedetails/154-Lt-Rusty-Dr-Naples-TX...?

It seems like someone is building sensibly sized homes there, however rare.

Yeah, the "newer ones" refers to the general trend of McMansions to expand in size even though not much else changes.

Square feet is such a bad measurement of a house, but it's easy to measure and state so it continues unabated.

You also have weird economies of scale where the first 1k sq ft of a house is much more expensive than the second 1k, and that continues basically until you're forced to use other construction methods (steel, for example).