In reply to mark k..

is how easy will they be able to move the pricing above the product picture in their woocommerce site, and neither of the frameworks are likely to make it easy.

The power of wordpress comes from the fact that any site owner that wants to rearrange the category list in the “meta” section of a post display, can google it, find some snippet, copy paste into the theme’s function.php and he is done. Can you see any non full time developer being able to set the tool chain to work with react or vue or whatever?
What does any of this have to do with the administration backend in WordPress? As I understand it the JS choice has nothing to do with replacing the current theme engine.