We started working on it at JuliaCon 2021, where it was at 22 seconds. See the issue that started the work:
https://github.com/SciML/DifferentialEquations.jl/issues/786. As you could see from the tweet, it's now at 0.1 seconds. That has been within one year.
Also, if you take a look at a tutorial, say the tutorial video from 2018,
https://youtu.be/KPEqYtEd-zY, you'll see that the code is still exactly the same an unbroken over the half decade. So no, compile times have only been worked on for about a year and code from half a decade ago still runs just fine.
