so here's the thing i was gonna say reactions but then there's latency so that's that
then i was gonna talk about ur constant strafing but it's a dm so you're probably practicing strafing in the first place ( you don't need to strafe that much in ranked and focus more on ur first shot accuracy)
ur crosshair placement and ur aim are good and improvement only comes from playing more you're not gonna find a magical recipe to improve fast
other points that are not shown in the video but worth mentioning (idk if ur good at them or not) is angle holding, and i mean very tight angles not the off ones
maybe u can train that a bit.
note: try NOT strafing when holding a tight angle don't jiggle too much imo gives u that good tracking aim (of course while spraying)
also spraying isn't bad tbh you just need to know when to use it
and my personal suggestion DM is ass to train ur aim go for the bots and do 30 bots challenge and the normal bots strafing one
EDIT: and lastly for ur own question about missing easy shots I would recommend playing 30 bots challenge on medium and work on micro adjustments, so don't go for flicks but rather point at the bot when he comes up then micro adjust ur aim to be on his head and shoot a youtuber called N0ted has a good video on that u should definitely watch
a pro with insane micro adjustment skills is none other than DA BEST yay if u want to see phenomenal first shot accuracy and micro adjusting go watch his games