Three Claude skills cover the whole life of a Shopify client repo at work, and after writing all three I'm fairly sure the steps are the least valuable thing in them. The value is the four or five places where the runbook is told to refuse.
Our template for new Shopify projects ships zero theme code, and the useful part turned out not to be the scaffolding at all but the taxonomy underneath it: which files the template owns, which the client owns, and which ones nobody should have shipped in the first place.
How our Shopify theme deploys went from someone running a push command on a laptop to one repo of reusable GitHub Actions workflows, and the backup-cleanup bug that had to get wrong three times before I stopped trying to be clever about it.
Shopify and Magento aren't really competing on features, they're competing on how much of your business logic you're allowed to have, and the answer depends less on your catalog than on whether you have engineers.
I spent a week being annoyed that the template language wouldn't let me do a thing, and then worked out that it wouldn't let anybody do that thing, on purpose, and that the restriction is most of why the platform works at all.