I have to respectfully disagree. I've had lots of Macs through the years. And I have many friends with them who don't use their Macs for anything particularly tough. Myself and others I know don't change up their computers very often. The need to upgrade is often driven by the Mac "running slow" as opposed to either some other part failing or some use case that only a more modern computer will solve. In the past, I would often tell friends to upgrade their RAM. Sometimes I'd do it for them. And I've also upgraded the RAM on my own Macs through the years (including recently on my 2018 mini, which I took from 8gb to 32gb). This invariably got the Mac to run faster to the point where it was acceptable and then happily used for several additional years.
This issue isn't about running today's software, it is running Apple's Mac OS that comes out four, five or even six years after the Mac in question was introduced. But since we can't do RAM upgrades, the advice I give and which I think is the right advice is to buy upgraded/more RAM now. The result will likely be several additional years of use out of the Mac. Alternatively it may be significantly better resale value as the person buying it at that time will pay more for those expected serval additional years of use. Looking at all of Apples M laptops, my advice is to spend the $200 and get it with the RAM at 16gb. I think that will result in slightly better performance now for most users from time to time and, much more importantly, dramatically better performance at some point several years from now. If the future of Mac OS and other software is like the last ten years, there will be a point in time in the future where the 8gb M1 and M2 Macs are basically unusable (or slow the point of being unpleasant to use), but the 16gb M1 and M2 Macs are still fully functional for many day to day uses.