I appreciate the goals and tenets of observability, but I really wish these tools didn't absolutely insist upon being integrated into my software.
Give me a log format and parse my logs and then do what you will with those logs to provide observability. All my logs are already json, and they're already relying upon convention for quick and easy parsing elsewhere, so adjusting the format isn't a big lift.
The last thing I want in between the innards of my application is communication with some external system (even if it's a sidecar) - especially if there is any sort of networking involved. If that sidecar drops or slows down, so does my application, which is a variable I'd rather not have to consider, and isn't necessarily tracked by the tools themselves.