Probably, the sign that it is a paradigm of the past, at least partially, are the issues Emacs has with UI blocking and multi-core usage. Great packages manage to mostly work around it, by outsourcing to other external processes and parsing the results, though the parsing happens inside Emacs. The issue and at the same time the enabler of many things, is the ton of global mutable state, that will be very hard to factor out at some point, if ever.