[Cthulhu_]

To add, cloning is one thing, but a lot of games - including id's own games - iterated on the formula, leading to the genre of first-person shooters like Quake, Unreal, Half-Life, Medal of Honor, Halo, Bioshock, etc.

That is, clones rarely work, but evolutions do. Stardew Valley on the surface can be considered a Harvest Moon clone, but it iterated on the formula, leading to a lot of attempts at casual farm games from many different competitors. Minecraft was an Infiniminer clone (or inspired by?) and iterated on the idea. Fortnite was a PUBG clone which was a DayZ clone.