Would anyone be able to look at one of my replays and help me figure out what I’m doing wrong?

I’m a high diamond to low gm puni player. He’s not quite my main as I flex usually but he’s my go to dps. I feel like I always have high deaths and sometimes it’s almost impossible to get final hits unless I’m in literal aim nirvana and hitting everything. I really just don’t know how to play him. My main way I guess is just sitting in front of the healers and just holding left click at everything in sight. If I try to take any off angles or do something a little risky I get PUNISHED bad. I’m also not good enough to do the crazy shit like zipline shotgun dive puni.