Komi-san herself is not the most original character in anime. In fact, the joke is that every character is pretty much the embodiment of a single defining character trait or archetypal trope which their name is also a pun of. By very nature they cannot be original. Even protagonist has a name that means something like "Just some guy." This is the real joke of the anime and where most of the fun I think comes from. All of the characters are these walking caricatures of themselves, but nobody seems to realize it. In fact it's more common that people are treated as being just the opposite of what their name and personality implies. The comedy springs from how blind people seem to be to very basic and obvious realities.
No one seems to bat an eye at how several people come to school dressed as a ninja or in plate armor or whatever. Pretty much everyone at that school is some sort of weirdo or degenerate but they all just keep acting like everything is perfectly normal here. It's fun to try and figure out how a person's name is a pun of their personality, though admittedly hard to for most of them if you're not a native Japanese speaker. The overarching goal of achieving 100 friends helps ground the story and give it a clear end goal, and I think it's a cute goal for someone who struggles to make friends and talk to people.
I don't know what the Japanese fascination with shy girl's is but they are apparently a really hot commodity at least among the artists and story writers that dictate what becomes popular in their media. I guess this is just the new meta for slice of life when it isn't just about 4 girls in some high school club. 8/10