Having one way of doing something and sticking with it even when better ways emerge is nonsensical imo.
f-strings are more readable (for me) and concise than string formatting or .format()
I do agree on the implementation front though, many of the other implementations are still on 2.7 or 3.6 at most, and don't have mainstream appeal. Made more with interop in mind (like ironpython with .net and jython with the jvm)