I actually meant trace ID and parent event ID (and ID was inferred). Parent comment is correct in that trace ID isnt technically needed, and is in fact quite controversial. Its an implementation level protocol optimization though, and unfortunately not an objective one. It creates an arbitrary grouping of these annotations - which is entirely subjective, and the spec struggles to reconcile - but its primarily because the technology to aggregate and/or query them would be far more difficult if you didn't keep that simple GUID.
It does have one positive benefit beyond that. If you lose data, or have disparate systems, its pretty easy to keep the Trace ID intact and still have better instrumentation than otherwise.
I am absolutely not seeing the problem you describe, I appreciate the ability to have a single ID for stuff that might go through several microservices. Helps us discover all data related to a single request-like entity in case of trouble. It already helped us trace semi-failed complex processes related to separate customers and we were able to manually fix things in a matter of minutes.
As said in other replies to you, I am still not at all clear what your issue with OTel is.
It does have one positive benefit beyond that. If you lose data, or have disparate systems, its pretty easy to keep the Trace ID intact and still have better instrumentation than otherwise.