Wanted to get thoughts around this:
https://github.com/airbytehq/airbyte/issues/8503
It seems like most of the focus was on the performance characteristics, but another thing to consider would be there's quite a bit more data you can retrieve from the Shopify GraphQL endpoint that doesn't exist in the rest API. It also seems like this is the direction Shopify is heading is the GraphQL endpoint being the preferred way to interface with Shopify. I wouldn't be surprised if the APIs continue to diverge over time.
One example is the customer journey data, this only exists in the GraphQL API and is quite important for understanding the data from a marketing perspective.
https://shopify.dev/api/admin-graphql/2022-01/objects/CustomerJourneySummary#fields