https://docs.mongodb.org/manual/reference/configuration-options/#operationProfiling.mode says

The level of database profiling, which inserts information about operation performance into standard output or a log file. Specify one of the following levels:

This controls what is stored in the profiling collection though not what is output to the logs or standard out, right? The wording contradicts, or at least confuses, the description for the operationProfiling.slowOpThresholdMs option:

MongoDB records all slow queries to the log, even when the database profiler is off.