I'm not sure why but I've noticed a trend with McCartney's clips.
The stuff on TV or elsewhere for public consumption seems to be with croakiness and warts a plenty in the singing.
A concert, seems to be completely devoid of those things. I know there is a ton you can do to sweeten live sound, but it's sort of unlikely they could tweak all of that out.
I'm thinking his touring schedule being somewhat limited now has lessened him keeping his voice ready at all times. Meaning these occasional bits do not have the benefits of the vocals being exercised beforehand as they used to be in the past.
Just an observation.
Hope he's having fun, I'm thankful he still likes to make music and tour on occasion