well he still has the drive to be the best.
beyond that though vegeta has had a ton of character growth time.
big one... he had kids.
his son came back in time and died causing vegata to awaken feelings he didn't even know he had.
from there he raised his kids, and then had one last major, I want to be a jerk moment becoming a bad guy for the sake of trying to be the best, knowing that death is trivial on earth and who ever he killed would just come back.
where by the end of all that he attempted to sacrifice himself to make up for his mistakes, aka already quite a changed man at that point.
but wait, then a bit later he is brought back only to admit that goku is his friend.
really nothing in super so far is out of line with what we saw vegeta become in Z. and it's not like it happened overnight. we have basically seen vegeta go from a 22 year old Jock to a near 40 year old family man. He still has that drive that made him strive to be great, but his priories are much different now. He not only wants to be a better man because of his time with goku and his family, but in general is.
because he would have lost the fight? (killing someone equals disqualification aka really the ultimate team would be made up of 5 people who instantly die when getting touched by anything

)
Vegeta hates losing.
also he knows that his wife wouldn't approve of him murdering someone and despite his attitude and pretending that he doesn't care, he is totally her bitch.
plus frost doesn't = freeza.