Say you have a dozen of full screen windows. That’s 3840 × 2160 × 3 bytes per window or 24MB, so our dozen windows take just shy of 300MB uncompressed. That’s n

Say you have a dozen of full screen windows. That’s 3840 × 2160 × 3 bytes per window or 24MB, so our dozen windows take just shy of 300MB uncompressed. That’s not nothing, but it’s also a small fraction of the RAM on even a phone for one of the primary functions of the device, and the upside is that you avoid all kinds of nasty challenges coordinating updates and access between applications and the window server because there’s no shared state between applications and the window manager can do things like transparency, scaling, or all-windows switching views without any app involvement. Another way of looking at this, Apple did the same move over a decade ago with far more limited hardware and pretty much everyone loved it because the speed and stability boost was quite noticeable.