Oh my.... yes. For me, that would have been Angular 1.x days. And while it was neat having a tool that could pull a deterministic flat list of dependencies, I wouldn't go back to those days. I do wholeheartedly agree that injecting core-js into every single build, in the rarest of cases that you'd need to support a browser that doesn't support generators, or some other featured added around 2015, is just plain silly. I cringe when I look at a dependency graph and see all those polyfills in my builds!!
Gone are the simple distribution channels, and all build pipelines have 100s of megabytes of legacy crap that nobody actually ever executes.
If you want to tell me your page is working in IE6, you're lying. It will break apart in all places.
Anybody remember bower and pikapkg? That was the peak in my opinion.