Also, "perceived" or "real"?

This reasoning is flawed in my opinion, because at the end of the day, the software still has to be paid for (for the people that want/need to make a living out of it), and customers wallet are finite.

Our attention is also a finite resource (24h a day max). We already see how this has been the cause for the enshittificaton of large swathes of software like social media where grabbing the attention for a few seconds more drives the main innovation...

> Then the statement "Stuff can't interoperate with c++" is true

Where is that statement? The statement I reacted to (and with some caveats) was the following: "Libraries written in C++ or Java can generally only be used by applications written in the same language. It is difficult to get an application written in Haskell or Java to invoke a library written in C++."

Which in my opinion is not true for the reason I mentioned.

> Nothing from c++ ever gets exposed

Depends what's your definition for "getting exposed". If you mean "no C++ feature from the language gets exposed" then it's mostly true (you can still wrap certain things like allocators, though painful, but there's certain C++ features that have no real equivalent in some target languages indeed). But you can definitely expose the functionality of C++ code through a C interface.

> Is it easy to write a nice C interface for C++ that makes heavy use of templates, smart pointers, and move semantics?

If the interface itself has or leaks those features, no that's not easy indeed. But if those do not leak, then they can be used internally yes.

My point was not that it's easy to wrap a currently existing C++ library that has modern features in its interface in a C interface, especially post-C++11.

But that if you design something from the ground up, then it's rather easy (with a certain set of constraints). My bad for not conveying that better.

You do lose the ability to use some features, that's true. Mostly RAII around the interface. You can still leverage it internally in the implementation, and if using context objects it would be even easier. The main pain point is if you want to let client of the library use their own allocators. It's still doable, but quite a pain.

Classes can be wrapped with a bit of effort. You do need to write the constructors and the destructors manually and invoke a pair of new/delete on the C side, but it's just as you would handle a type allocated by a C library itself. You'd use it the same way. You just have the liberty to have the implementation use (mostly) C++.