Also Chuck claimed/acted as if he was tired of Jimmy's shit but the truth of the matter is he loved Jimmy being a fuck up and a criminal while Chuck was the overachieving neglected son.
If that wasn't the case then why has Chuck gone out if his way to sabotage Jimmy at every turn when he makes an effort to apply himself and become good at his craft?
Chuck's motivations are best demonstrated by the scene where Chuck and his wife had Jimmy over for dinner. In that scene Chuck continually talked down Jimmy to his wife prior to his arrival only to have Jimmy completely win over his wife so much so that they were both laughing and telling jokes by the end of the dinner and it was like Chuck wasn't even there.
That's what drives him. He knows deep down Jimmy can become a great lawyer and if he does then what?
Chucks success as a lawyer and in general is the only thing he has over Jimmy. Without that he goes back to being the ignored, less charming brother just like he seemed to be in their own family.
Next season I expect Chuck to put Jimmy through the ringer before ultimately making him "bow" by demanding he not use the familily name (Chucks reasoning will be hes worked too hard to build hus name and doesn't want Jimmy using/ruining it) which will lead to James McGill becoming Saul Goodman.
We see is completely differently.
The only thing Chuck is jealous of imo is the fact that he has to work hard and be honest and he's always had to cover for Jimmy
and hasn't been afforded such opportunities in his life.
If he hadn't spent a lifetime of cleaning up his fuck ups I doubt he'd even care if Jimmy was great lawyer or not.
Again.
There's 1 side everyone else sees of Jimmy
And then there's the side Chuck sees and knows because he's had to help Jimmy too many times to count and clean up all of his messes.