When buying a computer, most people want it to last several years, with most PCs you can upgrade the RAM during the lifetime of the device. If you buy a modern Mac, you can't.
As time goes on new software will need more and more ram, but on a Mac you are stuck with what you got.
Sure, Apple uses a different way of managing RAM than windows, but that can only do so much. Sooner or later you will get to a point where it just isn't enough anymore. With eight gigs you will get there sooner than with 16.
Regarding your usecase, one thing you need to consider is that CPU intensive tasks does not equal RAM intensive tasks.
Copying a file is neither CPU nor RAM intesive, so it is a rather pointless test.
Docker instances depend highly on what they actually do for work weather or not they will use a lot of RAM, so it is a very inacurate test.
Web development is not as resoruce intensive as say video editing or running simulations.
For you 8GB RAM is fine, for an engineer, video editor, or even a finance analyst, 8GB is putiful.
Then we need to talk about value, I can get an Asus ExpertBook B1 B1402CVA for less than an M2 MacBook Air.
The ExpertBook is slightly heavier with slightly larger screen (but with lower resolution), it has 16GB RAM and 512GB storage space, both of which can be upgraded as the user's needs change.
The ExpertBook costs slightly less than the MacBook, so tell me, why should I pay more to get less?
Now, I realize it isn't that simple, both computers are suitable for different tasks, they run completely different OSes, and have different types of CPUs.