If new is not always better, then you’re stuck with the really hard job of knowing when it’s worth moving to the new thing.

Worse, you’ll be blinded by survivability bias. One easily notices the good rewrites and can easily ignore the bad ones.

Even worse, bad rewrites may be noticed in a place that a year or two ago was deemed a success story. I’ve seen many such cases due to misunderstandings or just political dynamics.

And lastly, don’t let that Engineer do Scala, they’ll brush off the compilation time regression and make all developers lives slightly worse (assuming the project is big enough)