> This is measurably untrue; modern computers have trouble with the Windows XP era of games a lot of the time. Many games require tinkering and some will just crash after a minute.

This is mostly the fault of games and not Windows. Software usually breaks because of unfounded assumptions, for example, that user documents are always at a specific location or that CPU frequency is always constant. Instead of using Windows API functions to retrieve the path or keep track of frequency, lazy developers often halfass the implementation, hardcode values into their code and that breaks sometime in the future when those API functions become meaningful.