Every character is capable of being the Main Point Of View for a story, but not every character is suitable for it.
See, every story has its own unique needs and parameters that must be filled. You have a cast of characters with legitimate reasons for existing and taking part in the story, but many of them don’t need to be in the spotlight. That kinda sounds like something a snotty theater teacher would say, but it has merit when talking about writing.
Let’s take the show Supernatural, for example. The show follows two brothers traversing America in a classic car hunting down evil creatures and saving people’s lives after a demon killed the boys’ mother. The story works because the brothers are the main focal points, each one having adequate screen time to change and grow and show us how their differences and similarities drive the story forward. The story, ultimately, is about their relationship and what they will do to save each other (spoiler: they really have no limits). The story would have been vastly different if their father had also had a main POV, or the only one, and so the story would have not been the story we have now, just because it would have been reshaped to fit around the father instead of the sons. Ultimately it would have been a new show.
In my own work, I’ve often struggled with deciding who should be the main POV for any given story, or if there should be several, or if I should give in and do ALL OF THEM because every character has something to say, right?
In my latest piece, I wrote several drafts with two main POVs that tanked every time. I wrote some pretty cool scenes and bits of dialogue that I’m just in love with, but they no longer work. I spent a lot of time going down rabbit holes and ending up not where I needed to be before I sat down and really examined the story. Once I did, the proverbial lightbulb went off.
I only have one character whose POV coincides with the story the most at this point. Being that it’s a series, I can shift POV for later segments as the story calls for it, but right now only one character’s journey suits the story needs.
It only took me, what, six months to figure that out?
But, everything in its own time, I suppose. Once I cut out the extra POVs and reshaped what was left, the story flowed out like water over a spillway. The lack of dead weight allowed the character breathing room, allowed her to take the reins and use her motivations to drive the story from scene to scene and bad mistake into worse mistake, and what came out was pretty damn awesome, though I am biased.
I have other characters who are absolutely essential to the entire story as a whole, and they may get a POV in their own time. Until then, this story only has room for one person to helm the ship.
That’s not the case with every book. Like Supernatural a story may require a second lead. Or three or four, or twenty if you’re George R. R. Martin. Ferreting out these characters may take some time, and you might need to go ahead and write nine or twelve drafts until you understand the story well enough to know what it needs. Even still, that exercise is not in vain. The more you write, the more you learn, the more you learn, the better writer you become.
Just don’t give up.