in my experience OData has several big issues:

- Overly verbose endpoint & request syntax: $expand, parenthesis and quotes in paths, actions etc.

- Exposes too much filtering control by default, allowing the consumer to do "bad things" on unindexed fields without steering them towards the happy path.

- Bad/lacking open source tooling for portals, mocks, examples, validation versus OpenAPI & graphQL.

It all smells like unpolished MS enterprise crap with only internal MS & SAP adoption TBH.