I hypothesize it's not useful because you're using grep. If you use a tool that can show you multiple lines all tied by a request ID, it becomes much more helpful.
I am quite often looking for patterns across thousands of requests. As an example, one thing I inherited didn’t even log how long each request took to serve. Sure, you find out how long a single request took, by comparing the first and last log entry, but that’s just not useful 99% of the time.
