[oneplane]

In a way it is a side-effect of attempting to bolt the same abstractions the 'old and complicated' system had on top of the 'new and lightweight' which essentially takes the problems of old and puts them back on top of the simple stuff.

Sometimes it doesn't happen like that, i.e. the whole clang-ir-llvm thing, but it often does (mostly during serialisation and API exports for third party consumption).

Take WSDL and XSD as an example, the idea was that you put your details in a file that can build on other abstractions and the result is a universal and portable format that allows any system to work with any other system. That failed of course because you end up exporting implementation details inside of those 'portable' abstracted specifications making it no longer portable because you now have to implement the exact same details on the 'consumer' side as well.

Comparable things happen with Protobuf and GRPC due to the same reasons. It's not as bad (yet) due to limitations on data formats you are allowed inside the protocol, and it makes it a bit more an RPC with message passing rather than a complete API encapsulation. If the maintainers can prevent it from eating in to serialisation of arbitrary objects it might even not end up all that bad after all. But that was the theory with XML as well and we all know how that worked out.