Luffy isn't becoming Yonko level until EOS. It's not pathetic it's logical progression. He needed a lot of plot bull shit to beat Doffy, Cracker and Kata. Z and S have shown nothing on G4 level.
Luffy is becoming PIRATE KING+ level at EOS. Old but not sick WB was the strongest yonko and primebeard was slightly weaker than sick Roger, and Luffy needs to be stronger than Roger to overturn the world and outdo Roger's accomplishments. Blackbeard will be stronger than Kaido by the time they fight, and then Luffy will need to take on Im.
G4 was physically quite significantly superior to Katakuri's physicals (when fresh), just couldn't deal with.
Tankman one shot Cracker, that whole fight was plot b.s. and snakeman should have been fast enough to tag and beat him.
Doffy was plot b.s. "one hit away from beating him before running out" to extend arc drama and show the weakness of G4 which has now been circumvented.
Sanji and Zoro have been training to get ready for this raid and haki blooms on the battlefield, they will both rise to the challenge.