As a normal, boring user that does nothing special other than browse the internet and the occasional "casual coding" -- what am I supposed to do with 32GiB of ram?
Title. Besides setting tmpfs to use 10GiB of it to store downloads.
Just wait. In 10 years 32 gig is on the low side to just run the OS. Hardware getest faster and bigger, but software scales with it.
The more resources are available, the more people will program computers to use them.
My first graphics card had 128mb memory. These days it goes in gigabyte and they use the memory and processing power to produce amazing things.
On the other hand, they also are not as critical on efficiëncy as used to be, because there are simply more resources available anyway. As a consequence, some programs use a silly amount of resources for basically doing nothing. Sometimes I really feel like my browser is eating RAM.....
A program that can run on 1GB but uses 2GB is more wasteful, OS and FS level caching and memory reclamation only work if the memory is available, and a program wasting it takes it from everything else, unused RAM is wasted, but so is RAM being used for no actual function.
Not to say programs cant use large amounts, but they should provide a level of functionality for the amount of memory used, and some programs of late have been more than a bit inefficient, in short, filling the RAM is good, but do make sure its actually being used.