tl;dr: "there is too many setting, most people won't even use them".
The solution IMO is not to remove those knobs completely, but to set defaults well and be able to 'pop under the hood' when you need as you probably know what you're doing by then.
A good use case is an editor - most recent successful editos such as Sublime, VSCode etc are minimalistic to begin with, but very configurable behind the scenes.
For starting user it's nothing but text editor, for an advanced user it can be a full blown, build, testing and deployment enviornment
Getting the 80/20 rule right on defaults is extremely important. I see this especially in well-written mobile sites, where the GUI complexity cost of configuration is higher.
When making Office 2007, the MS Office team had the problem that 99% of their feature requests were for features already existing. Users couldn't find them.
Their solution was a UI change, from menus and toolbars, to the oft-maligned Ribbon. Advanced settings were kept almost the same as in previous versions, and the button to access those was an arrow in the section containing common settings.
