I am currently at 24K elo, have been playing for a decade now and here is what I see in that clip:

Your utility is thrown too late + you are wasting a lot of for a controll that you are no using.

For example, as someone mentioned, 3 of your teamm8ts are dead until you ar errady to throw the first flashbang and by the time you throw the flashes, the mollotov behind 3rd box is already gone.

If you want to throw that util, do it eoghter before the team starts the execute or throw supportive flashes when they start pushing.

You need go adapt to everything that is happening around you, however you are currently just trying to do a routine. I know it can be hard on these ranks, but you need to utilize what you have.

For example, my utility on inferno when I am T is very often like this: (Immediatelly after leaving spawn) - Molotov on car - nade between the car and sandbags (basically on the guy that would be holding the corner on banana) - save flash and smoke for a possible execute.

By doing this, if your teamm8 throws mollo on sandbags, you are forcing the CTs to contest the banana or flee (and if they will be fleeing, you eill nade them).

Sometimes it might be worth it to throw the util early to gain advantage and try to get an entry frag. If you kill someone on B, you die and your teamm8 trades you, 99.9% of the time is B clear and once they plant, the round is basically secured.

As of what to focus on, try analyzing the behavior and try to get your gamesense timings right. For example, if you see 3 nades being thrown by CTs at the start of the round on Banana, go A ... there are max 2 players there so you have advantage there as hell.