I think OO has fallen out of fashion because there's a perception it can more easily lead to confusing code. While one can write confusing code using FP, it's not as easy to do.
Also writing confusing code is incredibly easy in any language / paradigm. One just has to be inexperienced thinker.
It's true. I haven't read much OO CS literature AFAIK. Do you have a some recommendations?
https://www.amazon.com/Component-Software-Object-Oriented-Pr...
The first edition uses Component Pascal instead,
https://www.amazon.com/Component-Software-Beyond-Object-Orie...
Then even if it hasn't taken the world by storm,
"Designing Object Oriented C++ Applications Using The Booch Method"
https://www.amazon.com/Designing-Object-Oriented-Application...
Assuming you also feel like reading about UML design stuff
"Object-Oriented Analysis and Design with Applications"
https://www.amazon.com/Object-Oriented-Analysis-Design-Appli...
Yes, it is.
It is in some situations easier to write non-confusing code in FP (though in other situations its easier in OO.)
Also, OO hasn’t really “fallen out of fashion”, its still, AFAIK, the dominant paradigm. It’s just not as hyperdominant as it was from the mid-90s through the -00s.