Plots are limited, and that’s a fact. If you think you can make up a unique plot all by yourself, think again. I’m not saying that it isn’t possible – maybe you can do it — but it’s as difficult as climbing Mt. Everest without oxygen.
Why is this so? Because there have been writers for centuries and centuries, and every plot you think of has already been done, been written or been told in one form or another. The details may be different – the characters may be different, and the setting may be different. But the plot will be similar; the issue of plagiarization will rise.
It’s a big claim to make. Is your writing original? Maybe you struggle with plots. Maybe you can’t seem to find a suitable plot.
Maybe it doesn’t fit.
Maybe it seems like it’s been done before, and many times.