Conversely, it's surprisingly difficult to get engineers to master things they aren't intrinsically interested in. We've had a stable tech stack and core architecture for 4+ years and one of my major challenges is to stop employees constantly trying to introduce $new/$shiny or major refactor X because it wasn't built how they personally would have done it and get them to just learn and understand the stack we already have - which addresses all our needs at most 5% less optimally than $new/$shiny.