What's the expected use for DataTables?

I’m experimenting with DataTables and I feel like I’m missing something. How are we supposed to use them?

a) Create and modify all data in JSON/CSV text file. Don’t deal with DataTable assets in the editor at all. Do everything in C++.

b) Use DataTable assets. The fact that they export to JSON/CSV is useless. All edits must be done in-editor. Reference assets from C++.

I guess my confusion is that these both work, but being able to import-export to/from CSV/JSON seems only useful once? Are we expected to manually export, edit data, then manually re-import over and over, if dealing with Data Table assets?

What does everyone do?