That's the point. Mumbai suburban has a FC. So suburban AC was priced higher.
Suburban FC has cushions. Hence at least 4 times ticket rates. AC was priced higher. They probably thought of competing with CABs.
With...
more... Metros coming in, railways might do away from FC and keep just 2 classes -- AC and NON-AC.
My last read in this regard was that MRVC placing orders for about 283 (10 % variance) AC rakes (12 coaches) with IR (mostly ICF) for deliveries beginning 2024. That could be hastened (?) Political --- stop.
I believe this is a good start. As new AC rakes arrive, MRVC should stop leakages, something like Metros (no leakages -- no W/t pax)
Mumbai Suburban are the fastest mode of transport. And they are cheapest. They can't be beaten by Metro.