In my opinion:
The reason they didn't oust Joe as President and allow a succession to take place is that Kamala isn't qualified to be President (her parents weren't citizens when she was born) and this would push Mike Johnson (R), who is Speaker of The House as President of the USA.
Thoughts?
The requirements to be VP are identical to the requirements for President. Kamala has been judged qualified already. This is not the reason.
Oh who judged?