I have a successful career in my real life. I am only able to spare barely 6-8 hours a week on Valorant.
I was Diamond before reset. Currently in Plat 1. While I encounter many smurfs in the game, I do not feel they are really OP. The aim is more or less the same beyond Diamond. The only change between a radiant and diamond in my opinion are they have more time to spend on the game and game sense is way better. They adapt faster based on the previous rounds.
It takes until Diamond to be able to predict proper crosshair placement and find the correct mouse sensitivity.
I use 160epi with Artisan Fx Zero. Players have to understand what is best for their style. There is no perfect sensitivity. I like low sens and my setup is low sens. I play Jett. Raze seems impossible. Neon is manageable.
Second point is calm aim is very important. you should not panic if someone is peeking you. Use AD even while holding so it makes it harder for your enemy to hit. (if budget permits, buy a wooting keyboard which helps in fast movements).
Having a good mental is important. If you cheer everyone or someone on the team cheers after a round loss, it keeps morale high for the following round. Comms are important aspect. When i solo queue and there are no comms, it is a guaranteed loss. Unless there is smurf on our team or someone in the team pops off that match.