"The New T1/Jewel Car Park Changi Airport’s new T1/Jewel car park, situated within the Jewel complex, opened in November 2018. The car park spans five underground levels from B2M to B5, with a total of 2,500 parking spaces. The new car park provides more than thrice the number of spaces as compared to the previous open-air car park at T1."
So with Jewel, now we have 3x the carpark space generating revenue like you said
and additional revenue from shop rentals
and jobs created
and the whole world instagram/tik tok Jewel as free publicity
.... like I said, no wonder opposition cannot make it