Many games launch with improper implementations, causing problems. Is not denuvos fault but it is one more thing to go wrong

Resources used for implementing denuvo and funds for ongoing support take away from the game development itself creating the possibility of less of a game. Denuvo is a subscription, so companies have to keep paying for it. Now they have to charge more for DLC to recover those costs. In both situations, the gamers suffer more than the companies.

DRM in general means you can't own that thing. Steam is easily cracked if steam went out of business but firaxis or denuvo? If they go under without patching the game then it's dead forever.

I don't know if anyone has done a study on denuvos effect on game sales, but there have been many studies on piracy itself that show not only does piracy not steal sales, it helps promote good games through word of mouth and the demo->purchase pipeline where users want online features after trying the game. Bad games don't get any boost but i think civ7 is safe there.