I too recommended and activated MSE mostly for old people/computer illiterates, just because it could be more familiar. Less "my computer is making squeaking sounds, I'm afraid to turn it back on" reports (kasperky did not have an option to turn off the detection sound for a while).
At the other end of the spectrum - the gamers, did not spent more than a few weeks with MSE. Why? Because of the horrific schedules and exclusion lists. It was simply overriding user choices, and doing that a lot. Trashing the HDD while playing a game, blocking popular no-cd's or other stuff people used to try out games (probably linked to a more aggressive move against piracy, that was dropped the next year).
What's left? The corporate level. I've only seen MSE on state-owned companies. If you already pay for MS support, why not. The others were reluctant to use a solution that was proven time and time again it's always too late. Even weeks late. And on top of it, it can break stuff by itself!
It did not take much time for the waves and waves of malware to target MSE specifically The whole fake-AV business started with this. So you had a nice and shiny icon in the systray, but in reality, it was dead and buried, or even worse, doing bad stuff. In all the 7 era, it was the easiest security solution to bypass. I've spent weeks cleaning up after systems "protected" by MSE.
What changed in 8 and 10? A lot. More robust. Better exclusion. It gets used for telemetry purposes.
What did not change in 8 and 10? A lot. Same level of protection: baseline - it all depends on your exposure (where you live, where you work, what you use) and on your luck to not get hit by first waves. Same horrific schedules. Same trashing of resources by the scanners.
So people, please stop recommending a critical software that you really did not put to use. Others might not be as lucky. Last thing, Malwarebytes is not divine - Ok, maybe their marketing is.
You know, I used MSE for a lot of years and never had even one instance of all the things you rant about. I play games and play from CD and never had a single issue with it. I never had a virus either. I pay attention to what web sites I go to and know what I am downloading and from who and have no cracked software. Maybe those things are the difference with your experience. I have never even heard of people complaining about most of what you are saying.
Get this straight, I am not recommending Defender as the only defense against malware. I am just saying that many people have used it, and MSE before it, with quite good results. Business users should never use it but home users can. I recently saw a test (I don't remember where and did not bookmark it) where they threw all kinds of malware at a Windows 10 system running the combination of Windows Defender and the free Malwarebytes Anti-Exploit and that system was virtually impregnable. Anti-Exploit is useless by itself since it has no signatures and relies strictly on behavioral and heuristic analysis. It picked up the new stuff and Defender blocked all of the known threats. It was pretty impressive. It was not 100% effective but really close to it.
As for Defender, do read my post "Edge Hijacking" where even with the aforesaid Windows Defender and Mbam plus Mbam anti exploit installed failed to protect my computer.
Having used the above since Oct last year without any problems, I have now decided they do not offer enough protection, and have installed Avira Free.