Companies wouldn't trust a third party to run binding technical assessment for them, and quality devs would probably avoid places that hire without having someone from the destination team show up
I think the opposite would be more beneficial: a light check to validate work claims and some high level foundational question about code just to make sure one has basic proficiency in what he claims he has
Then companies would need lot less hr pre-screening and could focus in technology and culture matching
If you can hire someone skilled, but who other companies might overlook, that's a huge benefit to your team.
Triplebyte is really just the first screen, and the importance each company wants to put on the signal is up to them.