Good analysis but I think that Sid was better before. He did support Roli in the early episodes of SSK
1. They got married and it was Sid's decision. So he supported her there. They became friends but they didn't understand each other much. Obviously it was because of their age difference. I would say Roli was rather immature during Mumbai track and before.
2. During Anila's track (Khushi's sister) RoSid and PreSim together worked and got rid of the problem. In those episodes Sid was shown as rather clever than now.
3. Sid started loving Roli and proposed to her but Roli rejected him. He still supported her as a friend.
4. During Khushi's track Roli would go up to Sid and complain about her feelings of Khushi. He would advise her the best to stay out of her but Roli was too bothered about her sister obviously. When Roli was told to leave the home, Sid left with her.
5. They moved into a new home and Sid told Roli to keep away from BW family. Roli not listening to Sid went in for her sister. So in a way she hurt him. Sid didn't listen to anything said about Simar but Roli could tell any other way.
6. When Simar couldn't become a mother, Sid searched and came up with the idea of surrogacy and even supported her when she said she will be the surrogate.
7. During Veeru's track Sid started to become stupid. He didn't believe Roli but Roli should have told him another way.
8. When Roli came back after being kidnapped Sid was ready to even strangle Jhanvi but Roli stopped him. Even when knowing she was his sister Roli told Sid to support her.
9. During Shaurya track Roli didn't tell Sid anything at all. She lied to him and hid things from him so it wasn't Sid to blame. When he came to know about it he supported Roli for her plan.
10. During Sonia/Khushi's track RoSid and PreSim solved the problem together.
11. During Jwala Devi's track they also solved it together
12. During Simar's death track Roli lied and hid things from Sid. Sid still supported her even though he was angry with her.
13. When Roli died and came back this is when Sid's dumbness reached the limit. The CVs are giving Sid such a stupid character and that of too like Prem was to Sid during Simar's track.
They have made Sid from super intelligent to super dumb. And they need to make Roli have some importance for her husband and not only her sister.