If the DPS and support are smart they should be standing behind you, or, at the very least, not in front of you. Genjis, Tracers and Reapers are just going to be wherever the battle takes them, and they should be pretty self sufficient. But McCrees, Junkrats, Torbjorns etc shouldn't be in the middle of the battle in the first place. I know often times shit starts breaking down and characters end up all over the place, but it all goes back to being aware of your character's strengths and weaknesses. If you're a junkrat or a Zenyatta or another healer or support...stay in the back, let the big boys take the damage.
A bubble would be really useful for a reaper right before he pops Death Blossum, but the problem there is right before I use it I'm typically out of sight, flanking, and you probably wouldn't have a line of sight on me anyway.
Edit: I'm talking more about the defending a point maps or the escorting the payload maps, I know in the contested point maps all hell breaks loose and characters can end up everywhere.
Edited by bob loblaw - 8/4/16 at 11:34am