The best way to improve at anything is always competition. Nobody ever teaches this, the most valuable of lessons.
Your parents always tried to teach you that you shouldn't be a "sore loser" and should also not gloat your victories. This is correct, in part. You _should_ actually be a "sore loser" to yourself.
If you like something, and you lose at it to someone better... you practice. And come back and beat them, causing them to practice to beat you, while you look for a new adversary. This is how all skills progress, how all inventions are improved upon, and how the human race (or anything evolves). Survival of the fittest.
The internet makes "skill acceleration" much more possible than every was imaginable. Years ago, you would be stuck trying to improve against your own world and what was available to you. Now if you can't find something "just a bit better than you", you just look somewhere else on the internet.
If you happen to be the very best at it (highly unlikely), you can rest assured that if you post your work on the internet, someone will try and beat you. And will provide you a new bar to reach for. And this will ALWAYS be the case.
What I'm trying to say is, never give up on something you like. And always invite healthy competition. Compare your work to someone who's work completely inspires you. Compare your work others that are doing the same, progress together, help each other by sharing your progress.
One day, I'll be able to draw as well as the people who's sketchbooks I look at daily. But on that day, they'll be able to draw like their current heroes, and I'll have to set a new goal for myself.
This is not to say you can't be happy with whatever level you reach, sometimes its enough. Or you have more than one drive / hobby / love in your life, and you need to get comfortable at a level in all of them. Work hard, and always have a goal.
Current Artist Level - Straight up begginer