They want to it for actual learning projects controlling things, instead of just running it as a general purpose computer.
Almost no actual projects where you use the Pi to control something really requires much memory.
It is basically using it as desktop computer that requires the memory.
I use one as a media server in a bedroom running Kodi. I got to think it would run faster with more ram. Also I want to setup one running piehole and my understanding is it would run much better with more ram, maybe even using a single unit for vpn server and piehole.
I'm no expert, just a hobbyist and I can usually figure stuff out with online research as needed so I could be off base on this assumption