One of the great advantages of being a festival programmer is that from the number of films one can see back to back it's fairly easy to find the commonalities in submissions. One that's most frequent, and is a pretty constant submission every year, are the stories featuring a man-child experiencing some kind of stasis. The character is usually in their 20s, however by every measure, job, school, personal relationships, they are years behind in relation to those around them.
As characters, they aren't inherently uninteresting. Nor are they that far removed from the world off-screen. What does make them lacking in heft at times though is how often in the films the characters haven't really been striving for anything. There's no hint of failed ambition. There's not much reference to any dreams. They are effectively automatons going through their routine.
There's nothing wrong with stillness, yet, even in stillness, there's potential energy. And in that potential is the chance to drill down to explore what makes that character unique. And out of that uniqueness can a film possibly standout and emerge as different.
If I had one specific piece of advice I would encourage writers and filmmakers to do is to find pursuits other than writing and filmmaking for these characters. Engineering, science, construction, business owner, stunt man, house painter, preacher...the list of jobs and professions that a character could find rewarding and find themselves is limitless, and less cliched.