The thing is, the VP's role is to be sort of 'seen...but not too often, heard....but not too loudly'. You didn't hear much from Joe when Barack was POTUS, either. And Pence was only trotted out when Doofus needed a boost with the religious right.
I think the problem that Kamala has had is that, being the first female and non-WASC' VP, she was thrust into the spotlight, expected to 'do great things', but then was relegated to the VP's usual role. This has been (erroneously to my mind) interpreted as 'not doing her job very well' when what she's doing is exactly what every other MALE veep has always done. Supporting the POTUS in the background and getting out HIS message, not their own.
I think she'll be Joe's running mate. To choose someone else would, in my opinion, alienate a sizeable portion of US Dem and Independent liberal voters.