Do you actually believe this?Any 1990's PC can browse the internet.
All pc's from the 1990's are single core and not alot of ram. Have you tried loading chrome on a single core machine with 512mb-1GB of ram with Windows 98 ( XP wasn't out until like 2001). Then try to go to any modern website. I guarantee you will stop in frustration within 15 mins. So I don't argee with this part.
And the your list seems to be mostly older games. Which would explain why you don't see a need to upgrade.