It seems that the M series machines have with the OS a miserable memory management system. If all was handled better, I would happily advocate with you that 8 gigs is more than enough. However, as some others as well have found a rather odd consistency of these machines to handle memory, - more seems to be a good temp remedy. As you pointed out, it is not just a 50 bucks upgrade (like a PC).Hmm, I've been using 8GB model for 3 weeks now and not once it showed any problems or case of instability. If the 16GB model cost just 50$ more, like if it was an additional RAM for PC, there wouldn't be question. But as it stands now, the choice should depend on given user case, i.e. planned tasks for the machine. IMO, 16GB in case of M1 currently is absolutely unnecessary for average home use.
I had like 10 instances of VLC player opened with videos and Chrome with 5-8 tabs and the most Mac used was about 6.8 GB of RAM. Actually, only few times I noticed it used swap file, it was after I run some games, and the swap file was under 1GB. Most of the time my Mini uses around 5-5.5GB of RAM (mainly Chrome).
Presently I have 3 tabs open (two consoles for NAS machines) and the other one right here. I also have messages open and VPN. The entire amount of RAM used, just over 15 gigs. Fortunately for me, I am not on a Mini here but another Mac M1 using far more RAM. For those of us who remember DOS days, paying attention to how to get upper space in memory was of great value and to control how apps behave. Sadly, seems with this amazing hardware, we would have memory contention issues. I'll again fully agree 8 gigs should be enough but in some instance it is not (when it could be).