> I encourage you to make a product even if something similar exists.

This is very good advice: we often give up on "great ideas" once we find that they have already been done.

But the vast majority of people we consider successful did not invent anything completely new, they just made a better kind of XYZ, sometimes not even that dramatically different. If you think about it, it's a much more logical path to success than expecting to be the next DaVinci.