I disagree, old projects are still accepting Bitcoin donation, some new projects also accept Bitcoin donation too.
It might due to tech winter hence not many people want to create a new project, they have more responsibility, so they don't have much time for fun.
The market is still bullish and there is not yet time for cryptocurrency winter season but I am happy if there are less altcoin projects created recently and in the future. I know it is not the fact but if it actually happens, it's good for many people as they will be exposed with less scam altcoin projects and it is helpful to protect them from many risky scam projects.
The fact is quite opposite as in bullish market, during bullish months, scammers will try to abuse the bullish trend and positive sentiment in the market in order to launch as most potential projects as possible. With positive sentiment, people are more easily convinced by new potential projects while the fact is painful. Potential projects will be tested by a bear market and most potential projects turn to dead, abandoned and scam projects in very first months of a bear market.