Theres defiantly a lot of free software that suffers from engineer UI but I find the UI of Apple and Google shockingly poor. Their UI focus is on encouraging the user to do what Google / Apple want not what the end user wants.
Free software gives people freedom to have what they want but figuring out what you want and setting it up takes effort. Many people are like dogs they don't think freedom is worth the effort if they can be kept by a master that feeds them regularly.
Often times achieving your desired result with free software is onerous, even if you know what you want know what you’re doing. This is a problem I’ve encountered several times just trying to achieve a desktop setup that works for me; I always eventually arrive at living with countless tiny issues or writing what I want from scratch.
Free software gives people freedom to have what they want but figuring out what you want and setting it up takes effort. Many people are like dogs they don't think freedom is worth the effort if they can be kept by a master that feeds them regularly.