The combination of xG and xGA was relegation standard. Their expected goal difference was 18th in the league (xGD/90 = -0.64).They couldn't score goals was their issue though. The had the 5th best defence (gkp are part of the defence) and the 4th worst attack. Even the stat you posted about xga wasn't relegation standard as it was 16th, not 18th.
And again, stats say he had a 76% or whatever save percentage, but how many were straight at him etc?
It is not easy to find good methods to measure goalkeeping. Statsbomb/fbref try looking at post shot xG. Their numbers from last season show that Wolves’ goalkeepers saved 8.5 goals more than what is expected/average. Best in the league with some margin.
For comparison, Pickford/Begovic comes out at -1.5. A ten goal swing on goalkeeper actions alone. And Pickford had a pretty good season.
Fbref goalkeeper stats