Bad advice tbh. I'm sure it's meant in the nicest way but honestly, look at how many coffeeshop aus there are in fanfic. Look at how many romcoms follow the same path. How many actions follow the same path. But they're all different because the author is different.
If it's already similar to something out there, but you want to do it, do it anyway. Because you're different. Because you did it it's something only you can do. Unless you're outright plagiarizing, it's already made different because it's your work.
Draw/write what you want to draw and ignore what's already out there. Don't hold up original and special and never before seen like it's the holy grail. Draw what you want to draw, because your work is something only you can draw. Tell people, even if meant to be taken well, that they should have to find something different and unique and special every time and never do something similar to anyone else is a good way to have a lot of creators doubting something they're passionate about because it's too similar.
(Quick someone tell the author of Haikyuu there were already several popular volleyball anime/manga and they should give up because it's not something only they can draw).