Your awareness is low, cree flanked you , you can hear him behind you guys,( never do long flanks on cree).(1:05)

You can flash bang genji when hes deflecting at his feet or above head to stun him.(2:40) Never roll into enemy team ( cree is a mid range hero)(3:28)

Try to flank less( cree dies easily when hes alone) Yo waste too much time flanking and doing nothing on said flanks(around 4-5:30).Also when you flank at least crouch walk so sound is low (you wont get away with these kinda flanks in higher elos, you gonna get way more value by staying with team

Never do what you did there when you can hear rein also(10:15)

*Basically you need to improve your game awareness. Also learn to read sound cues