I understand it's not fun that others just copy-paste your work (and usually make a worse game than you), but it's really not that bad. In the long run, the good ones are the ones being remembered. And that will drive a game forward. Take a look at a few classics:
-dune 2: easily the grand daddy of RTS'es. If others didn't ran with the formula and worked on it, we'd never had any of the grand strategy games or RTS'es of today
-doom: man...back in the days, reviewers even shamelessly wrote stuff like "this game is just a doom clone". Some of them were forgotten before they were even released (chasm: the rift, anyone?
). Others, like Serious Sam and (especially) Duke Nukem 3D had their own thing to add and became successful.
I could go on. And while those mentioned games could've sold even better if there weren't others trying to catch the genre, the very fact that it was copied meant that the very genre flourished and got improved upon. Same with minecraft, for example. You can boo out games like terraria or fallout 4 for riding the crafting idea created by minecraft, but these games still get sold and are just as good nonetheless (I'm making an assumption on the latter, obviously).
Aside from the obligatory (upcoming?) Lego world, Castleminer Z is the most obvious candidate. But a quick google quickly showed
some lists.