Your world is bigger.
I grew up in a small town in western Illinois farm country – you didn't have to be an Olympic athlete to be the best football player in town, and if you could insert a floppy disk into the drive right-side up, you could pretty much get a job in IT. Then, Al Gore invented the internet and all hell broke loose. Suddenly, we got to see our talents in stark contrast to the entire world, to the best of the best.
First, you have to understand that this is new and we're all learning to cope with it. We've never before had so much access to so much information, and we have no idea what to do with all of it.
Second, what's the alternative? I knew people who stayed in that small town because they didn't want to go away to college and suddenly be a small fish in a big pond. So, they got stuck – unwilling to let go of being the star quarterback or prom queen. Is that how you want to live?
You only see their best.
Your friends always seem to have it more together than you do. Realistically, though, you only see them after they've showered, shaved, and put on some clean clothes. You don't usually see them at 7:30am, changing their shirt because they just spilled half a cup of coffee down it while trying to eat a donut and check their email.
Likewise, you only see the tip of the iceberg of what people create online. Those same people have produced mountains of crap that never see the light of day (and, considering what does make it into public, some of it must be really awful). Of course, your mountain of crap is sitting on your desk staring right at you. Don't compare your worst to their best.
Do it anyway.
What if you could only read books by the "best" author or watch movies from the "best" director? Even pretending for a moment that there's such a thing as an objective "best" for artistic endeavors, wouldn't that be a sad world to live in? Humans thrive on variety, and our culture is constantly demanding more. There will always be more consumers than creators.
So, see what the competition has to offer, and do it anyway. There's room for more than one designer, writer, poet, singer, marine biologist, management consultant, etc. in the world. You don't have to be the best.
Best destroys better.
I almost ended this post with that last point, but this is important. "Best" is the stuff of perfectionism, and the great irony of getting discouraged and quitting anything because you're not the best is that you'll never get any better. The best weren't born that way – they were once 2nd best or maybe even 4,832nd best. So, get to work – worrying about best is just destroying any chance you have of becoming better.