How many people are thinking about, or have, created a custom eCommerce application, instead of using SCA? I am really beginning to think creating a modern React/Next/GraphQL application would be easier than trying to make SCA work for us. Especially with the REST Web Services NetSuite released.

Based on my experience discussing it with other people, this would be quite difficult. I have heard of people who have got very basic functionality to work, but you'll spend a lot (a lot!) of time getting some of the things we have created for SC to work. Eg, I believe just getting session stuff to work might be quite the challenge.