The algorithm (EBU R128) is designed to be very good at estimating the perceived loudness of an audio track for the average human ear.
Not only for a 3 minute pop song, but also for a 45 minutes avantgarde classical work.
And for movie scores (gunshots, long silences), commercials, podcasts, audiobooks, etc.
In my opinion it is doing a fantastic job in general.
But you can always make adjustments per track if you feel the need.