I have done some fairly extensive tests on the string splitting options and the JSON split methods and the STRING_SPLIT functions are by far the best performers if one is on 2016 or later, by far!
Encapsulating the output in a CTE with a ROW_NUMBER has proven to be accurate and consistent when it comes to the item's ordinals, hence my recommendation.
😎

Hopefully I will find the time to do a write-up soon