dwarf fortress has alot of fully original concepts, and has been in development for 20 years.
Vampire Survival released a few months ago, while Magic Survival was released a few years ago. They're extremely similar games.
I guess at the end it depends on what's your definition of rip off.
Is Torchlight a rip off of Diablo or do they just use similar mechanics and ideas?
Well, Torchlight had designers from Diablo 1 & 2 on the team as well as Diablo's composer/sound designer, so it's a bit of a special case.
Is League of Legends a DotA ripoff (the mod), or is DotA (the full game) a League of Legends ripoff?
Or at the very least, League, DOTA2, and HoN (may it soon RIP) are all equally rip-offs of the original mods.
But there's a lot of others like that. Hollow Knight is a better Metroid / Castlevania. Shadow of Tsushima is a better Assassin's Creed. Final Fantasy XIV is a better World of Warcraft. Dwarf Fortress is a better Rogue/Nethack. I will go into hiding now.
Strongly disagree about Hollow Knight, but it's greater than the sum of its parts.