Being a main character is where someone leads their life as though they’re the main character in a story. This is good when it lets someone feel agency and autonomy in their life. It’s a solution to being an NPC - a non-player character. An NPC is even worse than a main character. They go through life on auto-pilot, and talking with them feels like a closed dialog tree with an NPC in a game. “Main character” is generally considered an insult. It applies to the outspoken and interesting, but also jerks - the kinds of people who talk during a movie, play music in public places, or yell at waitstaff. “NPC” is also an insult - it’s like you’re an automaton with no agency.
It’s interesting that our society considers main character an insult. If you are too confident, you need to stop and stay in your lane. But not too much - you don’t want to be an NPC. This encourages you to be happy with being in the middle of the pack - not too outspoken, but not too docile.
More people could stand to be proactive main characters rather than coasting at the tip of the personality curve. The most interesting people are the main characters.