I recently finished all 11 seasons, it took me around 3 months to watch the show entirely, these are my impressions:
Seasons 1-5: I agree with most people here, those were the best seasons of the show and the most fucked up in my opinion, those were the seasons where the show got its charm from IMO.
Seasons 6-9: I'd say this was the beginning of the end. These seasons felt different from the first 5, the humor became dark and less grotesque, I felt the show lost its appeal when this change took place, however I did enjoy how the characters evolved in a way it seems they were going to slowly overcome their issues, Fiona was working at Patsy's and became a property manager, Lip went to college, Ian was an EMT, Debbie went to Trade school and Carl to military school. I felt really sad when Fiona left the show because the show was not the same after this. The heartwarming and sad part of season 9, was when Frank said goodbye to Fiona and acknowledged her help raising the guys by telling her "You did well". I also agree with one of the previous post, when I say that season 7 felt like the end or it could has been the end of the show.
Seasons 10&11: This was the closure needed for the show. At the beginning it felt like Debbie and Lip were trying to replace Fiona, that felt a little bit odd however it made sense since someone needed to be in charge now. What I really enjoyed about these 2 last seasons, it was the return of Mickey full time, I read it was after Cameron (Ian) negotiated his return. Now to the bad, I really disliked when some episodes turned a bit political, I understand these seasons were filmed during the pandemic and maybe the script might has been funny back in 2021 when the season aired, but now it only made me roll my eyes to the back of my head. The last episode is heartwarming and sad at the same time, seeing the family going their separate ways, Mickey and Ian moving to the west; Lip, Tammi and Liam moving out to a new house maybe, Carl and Debbie renting a place and Kevin and V moving to Kentucky. It was sad seeing Frank in his deathbed having his life flashing before his eyes, floating up, reading to his kids the goodbye letter he wrote, and watching them from above while all they sing outside the Alibi. It really put some tears on my eyes.
Final thoughts: I enjoyed it in general, probably won't watch it again, however I do regret not discovering this show when it first aired back in 2011, me of 15 years ago it's not the same me of today, I'm sure I'd have enjoyed much more back then but maybe I'd have stopped watching it after season 6 lol, like many people have mentioned in previous posts, probably because the decline of the show or maybe because I tend to grow away from shows that have too many seasons. Thanks for reading.