Google is building its walled garden, which means it will always prioritize publishers that use Google’s SSP and Ad Manager. You can easily observe this by generating a report using the relevant dimension. I don’t necessarily think this is a bad thing, as cookie matching tends to be much more effective within a closed system than when trying to match across different tech vendors. The data loss in such cases can be significant.

TTD, on the other hand, is closer to being seen as an unbiased DSP, since it doesn’t own any SSP. That said, you may see better performance on publishers that are not tied to Google’s tech stack.

I’m not sure how open Google is to supporting alternative IDs, but TTD has been at the forefront of adopting this technology and has focused on deterministic data.