There is a big difference between 100% JavaScript everywhere and having Vue component to manage cart state though.
A large majority of whizz bang the design team decides, can be done just with HTML 5 and CSS 3.
A large majority of whizz bang the design team decides, can be done just with HTML 5 and CSS 3.
Vue replaces the dom of wherever the app is, so the choice is between having everything within a single app div or having a ton of apps talking to each other. Given that the ton of apps solution still breaks fairly essential functionality (for online shopping) and requires a fair amount more structure it's a bit hard to see the benefits.