Exactly. Unlike Java where every object inherits from Ojbect, in C++ multiply inheriting from objects with a common base class is rare.

Some older C++ frameworks give all their objects a common base class. If that inheritance isn't virtual, developers may not be able to multiply inherit objects from that framework. That's fine, one can still inherit from classes outside the framework to "mix in" or add capabilities.

I've never understood the diamond pattern fear-mongering. It's just a rarely-encountered issue to keep in mind and handle appropriately.