I don't think the number of shitcoin projects are declining because there's around 21K coins right now on CoinMarketCap, few years before it's only 2K. Growing up from 2K to 21k for few years is really a huge number difference.
I think Shitcoins hype start since 2017 which is already 5 years right now and there's nothing changed so far.
Although I really hate shitcoins, but I don't see any sign shitcoins era will going to end.
Until everyone realize decentralization and privacy is a big concern, shitcoins era will end ASAP.
He was referring to the alt tokens that revolves around on the charity and games which was a hype because of Axie - NFT game and the charity was probably because of ShibaInu when Vitalik donated his coins to India for the covid situation.
Almost everyday there are people trying to shill these coins that they are the next big thing without even concrete plans or product. Its all just empty promises and most of the time they end up as rug pulls.