So, urban fantasy. This seems to be a huge no-no in rp and I'd like to know just why that is. Is it too common, are too many of the same scenarios used, do OCs from these verses suffer too much from Snowflake Syndrome or what?

I have a character I've been developing who's more like an amalgamation of concepts than anything, but I haven't worked too much on the world itself because idk if the idea would be too lazy or boring or what.