Surely it’s not because he thinks it will help him!
There is a big argument going on in the Democratic party about the sequencing of primaries for the 2024 White House race. Above is a table of what happened in the first four primaries last time and how Biden struggled in the first 3 but it all came good for him in South Carolina.
Now he wants 2024 primaries to start with South Carolina .
This looks like special pleading from the incumbent because clearly it would mean his effort to get the nomination would start with a big boost. Following the normal timetable and could mean some difficult going and that would be very risky for the 80 year old