Comment by znpy
I only partially agree. I recently got nostalgic and bought a 2nd-gen Core-i7 ThinkPad X220 from ebay (similar to what i had back in my university days).
It's generally very usable util you open firefox and browse a modern website. Chrome/chromium aren't any better.
The issue with old hardware is web browser and web pages, particularly web pages. Modern websites are incredible resource drains, it's unbelievable.
I can easily read documentation from old-school cool websites like https://pubs.opengroup.org/onlinepubs/9699919799/ but anything fancier than that gets the fan wheels spinning...
I don't notice any issues with an i5-6600k or an n100. Both are 4c/4t and extremely snappy. The only ways to get them above like 0.5 load are CPU intensive tasks like compiling, video editing, or games. The only thing I've found I can't do is real time viewing of 200 Mbit/s 4k60 10 bit 4:2:2 h265 off my camera because it's software decoded (software can only do ~half speed).