This is also because Google's Protobuf implementations aren't doing a very good job with avoiding unnecessary allocations. Gogoproto is better and it is possible to do even better, here is an example prototype I have put together for Go (even if you do not use the laziness part it is still much faster than Google's implementation): https://github.com/splunk/exp-lazyproto
Otel logs aim to record the execution context in the logs.
In languages when the context is implicitly passed (e.g. via thread-local storage / MDC in Java) Otel automatically injects trace id and span id in the logs emitted using your regular logging library (e.g. log4j). Then in your log backend you can make queries like "show me all log records of all services in my distributed system that were part of this particular user request".
Disclosure: I am an Otel contributor, working on logs (work-in-progress, not for production use yet).