The more corporate gaming becomes, the more statistics driven its design is, the more it stops surprising you.
So breakthrough classics tend to surprise the hell out of you, and have a lot to prove. Once proven, they are now an investment opportunity.
I would say though.... some first party games particularly for Sony and Nintendo, have been more interested in pushing a series forward to captivate fans and sell hardware.
I tend to prefer those kinds of sequels. Some games that may not be necessarily first party, are often still get their creativity backed by a hardware manufacturer to show off their product. Those can have interesting results too.
My difficulty with COD by name, is it is now just a formula. AC, is also just a formula. They have basically abandoned its whole meta-story now.
I would argue these are impressively good formulas, but most original fans stopped caring awhile ago because of increasing redundancy.
God of war for PS4 was a good example of a series surprising its audience and being a good showpiece. Would love to see more series try things like this.