I don't know why Chelsea will be faced with the option to sign Osimhen and Felix and they concluded that of Felix over Osimhen.
I know that the movement of Felix last time to the bridge wasn't a success. Although Chelsea were in their lows. Let us be hopeful that things might change now.
With the way Chelsea is buying many players of the same wing, I am suspecting that they are not only improving their squad depth but also very interested business wise to make some money out of these players.
I will never understand how and why Chelsea concludes to sign certain players. They have had their first defeat already and then they think Felix is the right guy to fix those problems. Last time he played at Stamford Bridge he scored 4 goals in 16 games. Bring that number up to a whole season and he might score about 10 goals. How is that what they are looking for? And that is not exception. His goal rate has always been at a goal every four games. It was the same when he played for Barcelona and when he played for Atletico Madrid. ATM is probably still angry about their decision back then as they paid a fortune for him when he came from Benfica. It's insane how these clubs go crazy when there is a young talent that plays one good season. They'll immediately pay three figure millions.

Joao Felix is set for a return to Stamford Bridge, deal complete.
I completely agree with @Dump3er. I don’t understand under which criteria do they sign and sell their players? After their new owner took over, everything has been wrong. They are selling Connor Gallagher one of the best performers of the last season. He was one of the best performers last season with Cole Palmer. What’s more, is that they give them ridiculous contracts. Many of them have 7-8 year long contracts.
And many of the players that they have signed have failed miserably. Lukaku, Mudryk, Caicedo, and even Enzo Fernandez none of them have performed like people had hoped. Almost all the new signings have flopped. And now they are selling one of their best performers from the last season. I don’t know how they make these decisions. The team is currently filled with young players who are unable to perform at the level that they are supposed to. Nkuknku is also another failure. He also hasn't performed like he was supposed to. Lukaku is also coming back to Chelsea. I wonder what his future will be.
Source: Sky Sports