Even with the nerfs to cypher, kj, and sage since they were released, sentinel in still the best agent role, especially now with chamber.
A team of 5 sentinels will stomp a team of 5 of any other role.
0/8, controllers are so much better. Omen is the most self sufficient agent in the game, Viper and Astra assert so much control on a map and are almost always great picks, and Brimstone and Jett are thicc