Technically they happened and many Democrats wanted Biden to debate, https://en.wikipedia.org/wiki/2024_Democratic_Party_presidential_debates_and_forums
However he declined. In general we don’t have an open primary when there is an incumbent. It may be a mistake, but that is what generally happens.
Also SOTU 2024 Biden was fine, so primary Biden 2023/2024 may also have been fine. The concern is if he can do it now and for the next four years. I think it’s possible, but he needs to prove it (or step aside).
We made some for the 4th. It’s not common but for parties? Everyone loves Jello Shots.