Better than Murray? yes absolutely. But Murray is 26 years old with 2 Stanley Cups, and has long term upside to be the #1 goalie for the Sens for a long time. He fits into the timing of their rebuild very well as well.
Better than Andersen? Depends on your context. He's played 75% of the games that Andersen has over the past 2 seasons, on a substantially better defensive team.
In 2018-19, Andersen was .4GAA and .015 Sv% better than his backup, in 19-20 Andersen was .8GAA and .023 sv% better than his backup. In 18-19 Kuemper was .5GAA and .022 sv% better than Raanta, who had very similar numbers to Hill. In 19-20, Kuemper was .4GAA and .007 sv% better than Raanta. Raanta's a better goalie than either Sparks or Hutchinson -- but you do have to be concerned that regardless of who plays net for the Coyotes, they all seem to put up really good numbers, whereas the guys who have played behind Andersen in the past 2 years have atrocious numbers.
It is very reasonable to believe that if Andersen had a competent backup, and/or played slightly fewer games, or a more defensive team infront of him, that his numbers would be much better than they are.
There is also the effect of the 2 years prior to the sample described above, where Andersen played 66 games each year and had very consistent .918 save percentages. Kuemper was a backup.