So, I originally ordered the 16GB ram 14" M1 Pro on launch day. Got it, used it, awesome. But I did some research, watched videos, did some of my own testing and even having several tabs open in the browser (which I do often), some decent sized programs, and high level multitasking, I was already using the swap. Granted, swap on these machines is so fast you wouldn't even really notice, but it's still not part of the unified memory (of which the graphics also share). As programs get larger over the years, pretty much normal every day stuff will go over 16GB and use the swap. If you want a safety zone for unified memory (especially since it is shared for the GPU) then I would say 32GB is the moderate to heavy user sweet spot if you have the money. If you don't have the money, then 16GB will be absolutely fine and you won't even really notice any difference. But with the 32, if you ever do need it there down the road, it will be there. These machines are not upgradable. So considering the high cost, a few hundred more is worth it so that you have the completeness you need. Just my opinion.
So, I returned my 16GB and upgraded to the 32GB (same 14" and 1TB ssd). Had to wait an extra month for it, but worth it to me if I am going to keep this for a few years. Just got charged. Apple's delivery dates are happening way sooner than expected.