I don't think the ones who seem to have stuff going on/matured in some areas regretted it. I think a lot of the OG's were strategic and read the room when deciding to leave.
Like apparently Hugo felt he was being phased out of storylines/screentime, so he decided to leave and see what he could make of his connections outside the show. Spencer allegedly left due to some drug problems behind the scenes and wanted to keep everything quiet to protect future opportunities. Lucy Watson said she left because things got serious with James Dunmore and they wanted to be away from the cameras and protect/focus on their relationship. I think Caggie probably didn't want to be remembered or dragged down by MIC and thought she could use the connections elsewhere and be taken seriously as a musician. She seems more frustrated and annoyed that people still bring up Spencer to her like he was the one who got away and vice versa because she didn't feel that way about him.
Not going to lie, I wondered why Jamie stayed on for so long as he has a successful business/stuff going on outside the show. I think he has a lot of faults but he is charming and seems to able to connect with diverse groups of people (something I don't see from a lot of the others who seem to stay in their posh bubbles). I think he even joked a few times that Spencer told him he is too old to be on MIC in his 30s and that it was time to grow up.
I think OG's like Francis and Proudlock did it right, popping in and out of the show from time to time. They had jobs going on and whole relationships sometimes separate from the show/ never seemed to take themselves too seriously and had easy-going energies.
I actually really like Proudluck. He seems very nice and like Jamie can get along with diverse groups of people. Also, I think his wife is very beautiful.
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