If you only want observability then it is save and easy to switch to/from LangFuse. Other features (if you care about) are more lock-in.

Also, it take some times for LangFuse to process spans and traces from the agents, so if you want to have visibility in milliseconds then that is not the option for you. But if few minute gap before code execution and traces being available to explore is not a problem, then Langfuse is good. Other than that I did not observe problems with it.