I'm pretty sure they still generate quite the revenue though not as much as it was back then but there are plenty of NFT with high trading volume, mainly those NFT like kaito and so on where just holding the NFT can get you an airdrop and therefore people are buying it.
But it's definitely just stagnating, despite the market for crypto entering another phase of bullrun, the NFT just stuck revenue also didn't move up that far it seems.