In 1977, Lotus presented us with the Lotus 78 which introduced ground effect to Formula One. A little while later, ground effect cars had become the de facto standard, despite the fact that a lot of constructors didn't even fully understand the concept.
In 2009, Brawn GP introduced the BGP 001 with its the double diffuser, which was deemed illegal by most other teams at first, but eagerly copied after it was declared legal by the FIA.
Copying other team's works, that's old hat. It had always been done, it will always be done. I really don't understand what all the fuss is about. Besides, after all the hubbub about Racing Point's "Mercedes," you'd expect the car to be far superior to all its direct rivals. It isn't. Mercedes and Red Bull are still vastly superior, even McLaren, Renault (and sometimes Ferrari, if they have a really good day, or rather, if Leclerc has a really good day) will still beat the, ahem, uber car.
All this makes Renault look like a sore loser and the FIA like the usual company that either ignores a problem until it's gone away or attacks the nut with a sledgehammer.