At some point I guess things became "good enough". The leap to Windows 95 was huge. The leap to Windows 2000 was huge. Leaps in hardware was huge as well around at that time.
It's many years ago I felt things started to plateau. When was the last time you were excited about a new processor? Or a bigger hard drive? If Microsoft makes their money from OEMs, and OEMs want to sell new hardware, I guess Windows needs to demand more resources... to keep the OEMs happy. TPM 2.0? For our security, or an easy way to sell new hardware, since Windows 10 will be "obsolete" and you "have" to upgrade to Windows 11.
And just to squeeze out some extra bucks, Microsoft discovered what Google and Facebook found out years ago... there is serious money in advertising.
I have an old Windows 8.1 PC in a corner. It has all I need, really. Enough disk and RAM for my usage (not a gamer).