There is nothing quite like working with a platform/language that you know inside and out, where you rarely have to stop and look something up, where you know t

There is nothing quite like working with a platform/language that you know inside and out, where you rarely have to stop and look something up, where you know the best way to do everything. It feels like flying a jet fighter, screaming along at Mach 3. On the other hand, although it can be frustrating puttering along with a new language/technology, googling some basic question every 10 minutes, that's how you learn, and sometimes you need language XX to accomplish task YY. Ultimately there is value to both, and as others have said, it depends on your goals. There will be times that call for learning a new stack and getting it done (even if it's coded badly), and times that call for expert application of masters-level deep magic.