This API can be used by users, not only services.
It is equivalent to “flashbots” private API.
The difference is that the service provider has a light check to know if the transaction might fail, and thus is not required to perform full tracing.
Once a transaction pass the validation, the provider should fully trace it. In case the transaction fails, it should drop it - and probably throttle down the caller, since this caller “lied”, by submitting a TX that reverts even if its preconditions are met.