Depending on your requirement. I think for normal use of computer 8 gb is more than enough but if you are a gamer or graphic designer some times even 12 gb is not enough for you to render high end games or graphic software.
Devaun Desktop can run on as little as 512MB of RAM and a single processor core. Tried it out in VirtualBox but there were some issues getting the wireless networking up in install phase when I tried to install it on bare metal. (which is typical of Debian based operating systems). Last time I ran Windows 10 it was on a dual core system with 6GB of RAM it was painfully slow taking nearly an entire day to update.
I would say generally consumers are not picky enough about their software. If people actually complained to the developers about software being poorly optimizaed and actually opted to buy other software or use open source. What gets me is that people will pay for software that barely works. Generally 8GB of RAM and a quad core is still enough to do most things you would do at the office. Spreadsheets, word processor, email, etc. It's enough to compile a new kernel and live build the system you are working with. Really depends on what you are doing with the system.
I was happy with 8GB of Ram till I started to host my own Discord channel. Then my computer crashed. I added 16GB of RAM and now the issue is that my processor can't use it all. But the channel worked to host 24 people.
I agree with many of the comments, it depends on what you need the computer for.
That being said, I think RAM more than any other component (with SSD following closely these days) gives you the biggest bang for buck in performance improvement.
Many people go out and buy a newer computer because of performance reasons, in my experience if their computer has capacity, simply doubling the RAM will give the performance benefits they are looking for.