Minimum system requirements
> Microsoft must have its reasons, but it appears that many of these restrictions are artificial and can be bypassed
As a software developer: We choose a minimum spec, and test our software on that spec. It may run on lower-spec PCs, at least most of the time. But then, after months of use, the user might find some part of the software that their PC is not powerful enough to run. They will then complain that our software is faulty. Err, no, the problem is that your PC doesn't meet the specs. "But it works, everything else runs". Err, no, if it worked you wouldn't be calling me.
And we may be conservative in our choice of minimum spec. If lowering the RAM requirement from 8GB to 4GB is only going to allow a few more people to run the software, but will cost us time testing and time optimizing code in future, then someone will make a business decision whether it is worth the cost of doing that for the small amount of extra revenue.
Also note that, over time, as the proportion of 4GB PCs drops, the extra revenue will drop but the cost of squeezing our code into a 4GB system remains, as we can't drop support for the existing users with 4GB RAM. Much better to spec 8GB minimum right from the start, so our code has room to grow as we add more features.