Trust me, I'm diamond 3
1 jett
2 killjoy
3 sage
4 phoenix
5 sova
6 cypher
7 yoru
8 reyna
9 brimstone
10 omen
11 viper
12 raze
13 breach
14 skye
Jett's ult is useful if you can aim and if you need to fight, Killjoy's ult is very useful if you have the gamesense to place it and teamwork to work around it to defend/retake a site
Both of them are used in very very different situations and they're both good at doing what they're supposed to do, and their inherent difference makes it pointless to compare them
Sage's ult is essentially making the game a 6v5 and is therefore the best in the game though