There are two problems with this thinking. 1.) The rewrite never seems to have all the features of the original (for many reasons), so you end up keeping the o

There are two problems with this thinking. 1.) The rewrite never seems to have all the features of the original (for many reasons), so you end up keeping the original around because science can be very niche. Now you have two or more packages to deal with. 2.) There is always a better language. Science (or at least parts of science) have switched before - from Fortran to C to C++ to Python. Some of the gains have materialized (some safety, performance, borrowing stuff from outside science). But it has come at a cost (language fragmentation, and also packaging is an absolute shit show right now, partly because #1). But I'm sure the next batch of languages will finally solve all our problems once and for all, and we will never have to switch again. (In general, I am talking about non-AI type science. I am a computational chemist, and our code really does date back > 40 years at times. That is not always a bad thing).