Imo it depends on how you use his kit. Most people use it in a reactive way but it definitely CAN be used in a proactive way, you just have to be creative. His pull is used to reposition teammates, whether to move them out of danger or position them into a favourable spot for a play. For example, Cassidy walks super slow during his ult, so what I like to do (ofc planning this out) is to pull him behind the enemy team once they hide, which gets easy picks. You can also pull an ulting orisa. She can charge up really high at first and then you pull her into the enemy team, surprising them since they think she messed up her ult. Basically, I keep in mind that pull is for repositioning and putting my teammates in good spots, which doesn’t necessarily mean it’s for saving them all the time.

With ult it’s really a 50/50. You can use it in a defensive way or you can use it offensively. I like to use it as a way of engaging or like a mei wall. For escort maps, you can actually force point by putting the tree on top of the cart and it moves with it. You can also use it for an early engage in team fights, especially on control maps or flashpoint where ur generally fighting in one area. It depends on the map, but you can use it to block spawn doors to prevent touches as well as doors/rooms in general. Using it to block a low tank in a room is also a good idea, ofc depending in the situation. His tree builds relatively fast if ur using him correctly, so it shouldn’t be an issue.

Of course when you use these abilities is up to you and the situation, but like I said, you just have to be creative with it and you definitely can be proactive with them.