Without that I think many would lose trust in Python and just switch language.
I mean it has only been 11 years since Python 3.1/2.7 and that's probably a common lifespan for maintenance mode code projects? 3.5 is still supported and that one is 5 years old. Why the hurry.
Because some people will always leave it to the last moment or beyond. Meanwhile the Python team has had the overhead of supporting more code than necessary.
Python is not technically superior to other languages enough that you can rhetorically ask that question. It’s main advantage is the ecosystem and network effects. If a bunch of people, especially the people who work on numpy, scipy, etc., decide to work on developing libraries for other languages like R and Julia, the data science ecosystem would switch over in a few years. Similarly for other fields people might switch to languages like Elixir, Haskell, OCaml, Go, Swift, Scala, Ruby, Kotlin, etc.
