In Jan 2022 my computer (I5-7400 cpu) of 4 years failed, I had purchased a 12 generation CPU (I5-12400) with H610 motherboard as replacement, while still using old 16GB DDR4 RAM and old power supply. After setting up the new PC (I5-12400 cpu);
(a) there is little lag on browsers and windows 10 applications;
(b) little or no issue with backing up or copying old files;
(c) no issue with uploading old files to OneDrive cloud storage;
(d) no lag or incomplete video on Youtube, etc.
Maybe the lags on previous PC could be caused by old/faulty motherboard issues.
I wonder if lags after Windows 10 updates, have to do with latest software upgrades are built for newer generation hardware.