I mean, sure, that's probably heavily influenced by the need for bundling for the frontend.
But it isn't done blindly. Bundlers reduce the overall size of the code, either due to minification or tree-shaking (removing unused modules). It also removes the filesystem overhead of resolving and opening other modules.
Would bundling be useful in other interpreted languages?
I suppose you may count JVM's compilation to bytecode as being very similar.
Lambda is certainly an interesting case for this, I’ll give you that. Outside of that, though, the impact on deployment speed is also not relevant; the bottlenecks for deployment are things like CI, canarying, even rolling blackout windows across AZs, etc. The actual time spent transmitting your build artifact over the network is completely negligible even at huge sizes