Great tutorials for exploiting RPi potential as a music transport - thank you.

You make a recurring recommendation among articles for the Pi 4 with 4GB RAM: may I request your technical reasoning in this - 4GB for headless servers? Are there specific needs of a given OS / process that benefit from 4GB vs., say, 2GB being too little memory or 8GB being overkill (granted on any 32-bit OS for a music transport, 8GB surely should be overkill…)?

I am interested based on how “cool” my Pi 3B+ units run; I’m aware Pi 4 B runs hotter, and I’m betting that heat turns up with every doubling of RAM? Thank you for any further input you can provide.