FWIW the "datadog doesn't like otel" thing is kind of old hat, and the story was a little more complicated at the time too.

Nowadays they're contributing more to the project directly and have built some support to embed the collector into their DD agent. Other vendors (splunk, dynatrace, new relic, grafana, honeycomb, sumo logic, etc.) contribute to the project a bunch and typically recommend using OTel to start instead of some custom stuff from before.

They support ingesting via otel (ie competing with other vendors for their customers) but won't support ingesting via their SDKs (they still try very hard to lock you in to their tooling).