1. quickly seeing which high level functions or methods take the longest time, 2. which methods are called a lot.
Even 2. can be of marginal use. A lot of times, it's not surprising a method is called a lot, and not clear whether those calls are indicative of a performance problem. There are times, though, where a method is called a lot more than you expected, in which case it might be the clue to solving the performance problem.
For 1., it's usually click down through the call stack for the most expensive top level method, while there is still a single method taking up a good fraction of the overall time.
Hopefully the stopping point will still be a method you wrote, and not a library call. If it's your code, you likely have the ability to fix the performance problem by changing your code. If it's a library call, you might need to be a little more creative, in finding an alternative approach, or better understanding what that library call is doing under the hood.
So for me, the profiler just tells me I'm looking at the right general part of the code when trying to improve performance, and that's about it.
In my experience, profilers are really low-level tools that often highlight the wrong problems, aren't very good at telling you where the optimization opportunities are, and tend to encourage microoptimization.
It's not that profilers are bad, it's that I get the feeling the people parroting this advice have no idea what they're talking about, and somehow believe that a profiler is "the solution", when profilers are neither necessary nor (most problematically) sufficient to fix most performance problems.