Depends on what cards you're talking about. The RX 5500 is about on par with the GTX 1660. The RX 5700 is about on par with the RTX 2060 Super. And so on. The Nvidia cards run cooler. Any comparison pretty much has to be based on either price or specifically what game you are most concerned with because every card from both camps performs differently depending on the game AND on what other hardware is in play. There is never just a "this card is better than this card" without the criteria to make that valid.