I think you're confusing "OOP is used in projects and I've seen accidental complexity in projects" with "OOP generates accidental complexity".
The truth of the matter is that developers create complexity. It just so happens that the vast majority use OOP.
I challenge you to a) start by stating what you think OOP is, b) present any approach that does not use OOP and does not end up with the same problems, if not worse.
B. Functions and structs.
I see you opt to go with a huge amount of handwaving over the question.
> Functions and structs.
That's what a class is, and thus OOP, except it supports information hiding and interfaces. So your alternative to OOP is... OOP?
Compare e.g. to "What should a language have instead of Lua-like tables? Maps and vectors" — "But that's what a table is, so your alternative to tables is... tables?"