If we are talking about gaming systems and casual PC usage, I could see your point, but that is not all that there is.
As a SOHO user, I have several machines of this vintage that houses engineering and CAD tools that are tied to those machines. If I update those machines, I loose the licenses and have to purchase a new license, or in many cases the vendor has gone to subscription only resulting in a phenomenal annual cost increase for no real improvement in feature set. I never go onto the Internet with those machines after EoL, on both the OS and browsers (Firefox usually).
We are talking over $12K in licenses on the CAD machine. The other machines are loading with legacy software with their licenses, with some no longer offered or defunct. One PC is set up to talk to the old scopes that I have, as well as other old equipment. These are on separate gapped networks with no outside visibility, but boy a maligned USB drive in a scope would wreak havoc. That equipment includes some 2001 1GHz scopes (and others), a 2016 power supply that puts out 140A, and even an Agilent spectrum analyzer. That equipment would cost part of a new house to replace, just to get new OSes on the PCs.
For the casual home user, it does make moving to a Linux platform look attractive. Except there is no easy support for the simple home user. My sister would have no idea how to fix apps not running on Ubuntu. So soon, I will have to move her to a W11 box and teach her all over again how to use it.