The RCW/CCW approach is much more low level, to the point there are whole books on how to use COM in .NET, whereas it was just part of how to program in VB (pre-.NET).
It also went through two reboots.
So now you have .NET COM support for .NET Framework, COM/WinRT support for UWP, modern .NET support for COM.
Every variation with its own APIs, only the classical .NET Framework approach has Visual Studio "import COM component" support, and none of them as easy as VB 6 was in the end.
Quite bad as developer experience, given the COM focus since Windows Vista.
[0] https://learn.microsoft.com/en-us/lifecycle/products/microso...
How long that will be remains to be seen. But Windows still ships the VB6 runtime (MSVBVM60.DLL) in the box today, 27 years since it was first released: https://learn.microsoft.com/en-us/previous-versions/visualst...
I suspect that .NET will last just as long given the sheer amount of enterprise software that was written for it - even today there are places that target it in lieu of the new OS-independent .NET versions.