I think the main problem is that people try to shoehorn OOP mechanics into everything, leading to code that is hard to understand. Not to mention that this is basically encouraged by companies as well, to look “futuristic”. A great example of this approach going horribly wrong is FizzBuzz Enterprise Edition.

OOP can be great to abstract complex concepts into a more human readable format, especially when it comes to states. But overall it should be used rarely, as it creates a giant code overhead, and only as far as actually needed.

Because of inheritance.

There are common traps and employer don’t spend money/time to train their devs to avoid them.

SOLID principles are pretty decent but a surprising number of people don’t do any of them

People (sometimes) use it far too much and in wrong ways.

Like inherit when you could just instantiate, or use a template.

Or when “everything should be a class” was also a bummer (inhetit “run()”), like I’d instantiate “main” twice (cool if it had worked I guess).

Or old code written by “wizards” where they cast cast cast instances onto other classes to use specific behaviour in crazily dangerous manners. And you’re the one to “fix it” because it doesn’t work well…

Otherwise OOP is good.

Multiple inheritance

It seriously gets in the way of just winging it.

If you ask me, the only reason for objects to exist are for preventing stale references. Anything more than this is unnecessary.