Before the 3DS and Vita, some handheld processors were so weak that it's practically impossible to compare their performance against modern gaming hardware....and yet we played those Game Boy Colors for 1000's of hours!
Tom & Dan discuss the era of handheld gaming from the 90's and early 2000's - Gameboy to PSP.
https://en.wikipedia.org/wiki/Game_Boy
https://en.wikipedia.org/wiki/Game_Gear#Technical_specifications
https://en.wikipedia.org/wiki/Nintendo_DS
https://www.ign.com/articles/2003/07/29/psp-specs-revealed
https://en.wikipedia.org/wiki/PlayStation_Portable
https://www.usinflationcalculator.com/