I don't think the precise protection model used to keep a system clean is all that important. What is important is that whatever protection model one adopts should be as close to 100 % efficiency, 100 % of the time. And therein lies the rub... the only IT protection model that approaches that level is absolute default-deny (non-execution). Absolute default-deny also includes reduction of attack surface. It also includes modified human behavior. Three simple concepts that are easy for the layperson to grasp - but seemingly - impossible for the typical user to follow - especially the behavior modification part.
LOL... if people would simply use the Standard User Account - all the time - then they would be more than 3/4 of the way to default-deny -- and without any real need for security softs other than what is shipped with Windows. Windows already gives users just about everything they need to stay safe - but it is people's expectations, lack of discipline, ignorance, complete disregard for safe computing habits, etc - that unravels just about every security mechanism built-in to Windows. Same can be said of just about any other security soft. Many typical users think their computer and digital devices are indecipherable boogey-men devices...
I think the average PC user has no inclination whatsoever to learn about any security soft - regardless of its ease-of-use. Their mentality is: "I will buy the best rated, most recommended AV - install it and forget about it - and I will be protected - no matter what I do - because it is the best. Afterall, I paid $100 for it..."
Sad fact is that in 99% of cases like above that security soft causes problems - whether paid or free - and the user quickly uninstalls it.
If it ain't plug-and-play - most people don't want it...