While what you're saying sounds nice, your theory has nothing to do with practice.
In reality, the ultimate source of this problem is the mismatch in speed between silicon logic and silicon memory. This is why your CPU ends up doing all sorts of tricks like caching, branch prediction, speculative execution to compensate for slow memory.
This feels like a lot of work being taken for granted. That is why support services exist. You pay a fee and the developer agrees to fix things for you. Open-source doesn't have to be for free.
You clearly haven't tried neither elementary nor Linux in general. There are many legitimate reasons why you might want to use elementary just as well as there are many legitimate reasons why you might want to use macOS. You're condemning diversity? To each their own.
I think one needs to also highlight the differences.
mac OS is built by one major player and they have a clear direction of where they want to take this. Linux, in general, is built by communities of people who may or may not have diverging opinions, priorities and interests. While this gives you a lot diversity, it can be quite problematic.
The financial aspect is also important. elementary LLC itself, has only 2 full-time employees, while Apple is sitting on a pile of cash. Yes, elementary builds on a solid open-source base [1] built by thousands of developers world-wide, some volunteers, some employees, but it's still a significant difference.
Having a smaller scale, it means elementary can be more agile in its changes. This also means that there is smaller testing base, which means there will be more bugs. The nice part is that, when you find a bug, you can help fix it [2].
In reality, the ultimate source of this problem is the mismatch in speed between silicon logic and silicon memory. This is why your CPU ends up doing all sorts of tricks like caching, branch prediction, speculative execution to compensate for slow memory.