One of the things I didn't like about Debian based systems (fun fact: Ubuntu is Debian based too so Mint is Debian based too) is APT. It's slow, ugly, it's just... bad. Nala fixes EVERYTHING.
Makes downloading packages from cli a lot more fun (not that you need to download it from the cli)
It should look much better and be slightly faster than apt. Therefore, this is a great replacement for apt.