I have been using Linux on the desktop since the late 90's. Other than increase hardware support, I have not tangentially noticed/felt almost anything you have mentioned here. When I fire up the desktop and load Firefox, I do not feel or see the sandboxing, the scheduler, the file system or the I/O. It just works.

Yes, we interact with it all the time but it isn't something that the end user would notice and that is a great thing. If you are not directly poking around with that stuff, you shouldn't notice it.

That they are so seamless should be seen as a badge of honor.