My most impactful project was the one that I coded quickly in three hours for fun. It has later turned into the greatest Turkish social platform in the world, is still being used by millions of people every day 26 years after I coded it.
I'm glad that you weren't there as the self-proclaimed arbiter of real impact™ when I started writing it. :)
So? I achieved things of my own as well, some of which I'm very proud of, but I don't go online belittling others acting as "holier than thou" to bring my point across, which you apparently do, I doubt you are as important as you claim to be.
Let me get back to the topic and give you another example that you might relate more: "just a hobby, won't be big and professional like gnu". If Linus Torvalds had taken his own thoughts on the impact of his work seriously and decided to pursue other "more impactful" whatever he saw at the time as you suggested instead of this pleasure-driven endeavor, Linux would have never happened.