Anton Kaplia

It could be quite uncertain. Due Magento saves the mentioned entities in a database the introduction of config like this will cause the question is this data that were declared...

@sydekumf one more question, in the examples you mentioned could EAV attributes be replaced with extension attributes which are already declarative? https://devdocs.magento.com/guides/v2.3/extension-dev-guide/attributes.html#extension

This is a backward-incompatible change that will break all the existing clients. Please be aware that the module was release and actively in use by clients.