Sadly I think you are right. Fixing the nouveau driver, and particularly for older cards, is an open-ended problem.
Officially Nvidia only supports the GeForce 7600 hardware in driver version 304. But driver version 304 is too old for inclusion in Ubuntu 20.04.
A newer Nvidia card (and using the latest proprietary Nvidia driver) would also have solved the problem.
Sadly I think you are right. Fixing the nouveau driver, and particularly for older cards, is an open-ended problem.
Officially Nvidia only supports the GeForce 7600 hardware in driver version 304. But driver version 304 is too old for inclusion in Ubuntu 20.04.
A newer Nvidia card (and using the latest proprietary Nvidia driver) would also have solved the problem.