These are good, but if you need to customize further, you interface with the toolkit (which only allows you to go so far), or you eject entirely.
Many people think it's time wasted to really understand how to setup and use (individually) webpack and babel and friends. I disagree because if you ever do need to dig in to these tools, since you've used them individually, you understand what you need to change.
If you eject from a toolkit but don't understand the underlying tools, you could be up a creek without a paddle. So you can certainly make things simpler, but you can't replace having the experience and understanding of what each individual tool does, and how to interface with it.
I would say the ecosystem changes, in aggregate, are probably a loss for new programmers. You have a much wider API surface to be aware of when using all the tools and how to integrate them. But for a senior front end engineer, it's unlocked the ability to have very fine grained control over the bundles you're creating.