Okay, that's fair. I certainly can't disagree that setting up a new web app in the modern style, from scratch and without prior experience, is cognitively heavy

Okay, that's fair. I certainly can't disagree that setting up a new web app in the modern style, from scratch and without prior experience, is cognitively heavyweight, and that reducing that complexity wherever possible is valuable. I would say that CRA's cognitive overhead, in a situation like that, isn't all that different from that of Rails, for example. They're both trying to do a very similar thing, albeit with very different approaches, and they're both very much of the convention-over-configuration school, which attempts to trade off not having to think very much at first about decisions you may not have enough information to make well, with making those decisions costlier later on once you do have enough knowledge to approach them. I have reservations about that entire school of thought, but despite them, my experiences with Rails and with CRA lead me to think that CRA does a generally much better job with those tradeoffs than Rails ever managed.