Why can't we all just get along?

Built a new computer 3 days ago, used the same hard drive and jerry rigged my parts into my wifes computer (motherboard, CPU, GPU, AIO, RAM) and done the same with her stuff to our TV computer, I do this routinely about every 2-3 years.

At first I could not activate Windows, it just would never open my account when the popup happened, it would show up and instantly close. So I re-installed Windows, that took the whole day to jerry rig stuff, screw and unscrew parts, get all the fans and hard drives swapped around.

2 days later I was STILL having issues. Steam would not load, YouTube videos would buffer forever, games would load into a white screen before eventually loading up and run slow at times, websites not loading, the list went on.

Turned out I had to go into the Bios and enable MCR, Power Down had to be enabled, EXPO turned on, I manually tuned my RAM settings so the FCLK=MCLK and set it to a certain setting and whatever else I also changed, it took me three whole days to get this up and running.

AMD works out of the box under certain scenarios, with certain RAM and CPU combos, do anything different and you have to go into your settings and tune the thing to make it work.

Intel needs XMP turned on, Windows requires secure boot and Platform Trust Technology turned on or you cannot install the latest version.

Apple doesn't play nice with Android, who doesn't play nice with Windows, who won't play nice with Apple.

Razer hates everyone and to get Synapse working you need a PHD.

Games won't work on MaxOS without some help from StackOverflow.

Linux needs a Windows emulator to run, and even that might not work.

At work I have customers who use Mac sending files I cannot open on Windows.

The list really does go on, but why? Why after 35 odd years of having home PC's have things generally not gotten better, if anything, it has all gone worse. 20 years ago you could put a computer together, install Windows and call it a day, now you need to know your way around the BIOS or pay someone to do it for you.

Why can't we all just play nice, have stuff work on all platforms and have all OS work together while ensuring things like MCR, EXPO/XMP and anything else is just on the right setting, the setting with the lowest issue rate and highest change to run to begin with?