The ending was completely retarded and makes zero fucking sense.
Jimmy went 8 years not feeling a single ounce of guilt, instead comitting more crimes just because he was bored and missed sceming, managed to get himself a practically nothing sentence and walk scot free right back into his old life that he so dearly missed (He was watching the tapes nonstop to the point where they literally melt down and his modern "boring" life is in greyscale to signify how boring it is), then decided to throw it all away in the name of (basically) imaginary pussy that he'd never get to claim.
You can't do 5.9 seasons of remoseless crime, spend the intro of every season and every episode outlining how much the main character loves crime and misses the good old days, then have the finale be "I confess to everything I'm so sorry and so guilty lock me up and throw away the key

"
And since when did jimmy give a *fuck* about chuck since the tape incident? Yes, jimmy did care about chuck AT FIRST, but after the truth came out its repeatedly made abundantly clear that the only feeling he (rightfully) had toward chuck after that point was indifference and/or hatred. Him confessing to chuck's suicide makes no sense on additional levels.
The ending just does not fit the show or the characters.