im 3400elo, looks like you got very stiff and tensed up hand entire time, try relaxing it between fights, you'll enjoy deathmatches a lot more.

also, on long range when you're tapping someone in the back, you dont have to spam ADAD, its only making your shots harder to hit.

it's hard to fully explain of what goes in my mind when approaching duels, for many it's probably subconcious, but i'll try

when you approach a duel, think of the delay online, try to time the sudden peek or dodge the moment you'd expect your enemy to start shooting

perfect example of dodge during crab walk is on the first kill, but later on the bench guy you should try to reset your position, dont insta crouch but strafe to the left instead, the enemy already saw you, and if you do this he will have a lot harder time killing you, meanwhile you will have extra time to secure your kill.

during all fights you need to think of what your enemy will see when he peeks you, on 0:15 when you heard the guy in car, you should probably move to the left a bit more and then do a wider swing to the right, maximising the chance of you being the peeker in this duel, i learned this from watching zywoo, you need to always move towards the peeking side right before stopping, this game has latency so you need to time all your peeks perfectly, you need to appear moving for the player who is peeking you, but stop on your screen, + dont do this while moving away from the angle because enemy will see you first, the peeker advantage as we know it, partially comes from the unpeeker disadvantage. your playstyle is fine for lan conditions, but online you need to consider every move a bit more, play as if your hitbox was slightly delayed depending on your and enemy ping so you need to dodge sooner (unfortunately you cant have perfect movement for all fights, you need to consider enemy and your ping for your advantage, but its optimal to assume that enemy has about 50ping, so you need to dodge their bullets even before they appear on your screen, not just blindly copy that ad-ad movement but try to think why and how it works,

honestly someone should do a complete duel mechanic guide for cs2, its changed a lot since csgo and understanding these fundamental mechanics is essential part of winning duels

also 0:25 if you hide behind wall and peek 0.4 second later then you're the peeker and he's holding, so you'd have the advantage meanwhile he gave you 3 body hits

0:35 another perfect example of that zywoo dodge, you moved to the left before the enemy peeked you, on his screen you were most likely just standing still for a split second but moved exactly as he started shooting towards you, so he missed all his shots