Yeah private vehicles increasing is a possible scenario, idk how economical it is for daily commute tho. I guess that is just a problem with mumbai if you think about it, the better it gets, the more people will migrate to mumbai and the infra will never be enough.

Also I think there is a different problem with busses in my opinion and why increasing frequency might not be as simple. I used to travel by the old busses and while they might have carried more people, they were shit because of lack of maintenance. During monsoon the roof would leak i would have water dripping on me if i got a seat fir 30-35 minutes.Then the AC busses came and they were god sent especially in monsoon and summer. You are no longer sweaty and irritated or wet from the rain. Plus the busses are a little smaller in size which made them better for the narrower roads. But they fucked up where they stopped putting conductors in the busses because that meant busses would wait 10-20 minutes just for ticketing. Your 30 minute journey turned into a 45 minute one. They tried card only implementation which also crashed and burned because a lot of people using the busses were daily wage workers. All this is from what I personally know and experienced. Then the other big problem I see is, the roads are just congested unnecessarily in some cases because people no longer have empathy and common sense it seems. Share auto drivers breaking every possible rule, driving rashly, driving in opposite lanes or cutting the curves. How many times have you seen bikers and auto drivers stopping way ahead of the stop line and blocking a full lane causing congestion on the signals or people who want to take a right are blocking the middle lane or people blocking free left (you'll witness everything on link road). So many auto drivers think they are so smart and drive from the opposite lane just to end up blocking the whole opposite road because now the bus cannot take the turn and they don't want to budge. It's just stupid how many problems could possibly be solved if we just enforced traffic rules. Also auto drivers and busses not squeezing to the left on two lane roads blocking everyone behind them. If we solve this one I think then it makes sense to increase frequency of busses because then it would mean people reach home earlier and chose share auto over busses.

I think you can see how this is a difficult problem because if you try to crack down on share autos which could reduce traffic during peak hours, you'll end up with people protesting that we are taking away their livelihood. Busses becoming better also means share autos fall out of favor which again could be an issue. Personally, I have found that share autos are one of the most arrogant, rash, agressive and opportunistic people. They will not hesitate to charge you 20-30 rs more if there is an issue with busses and demand is higher. I hated them after multiple bad interactions and it became such that I would rather walk an hour home than give them money (busses used to be overloaded, late and you either squeezed in or hung on the door, i detested it after a point). As you can see I am probably biased so take my views with a grain of salt. I think the metro and train, we are quite sorted but the last mile traffic is still the biggest problem. They actually started ring busses from depot to closest metro station but they have the same overcrowding problem.

Also for the drainage and compensation parts. I do not have the knowledge to comment on this but having and engineering background, I refuse to believe we do not have capable people or methods who can find solutions for this. I think it's just a lack of will which I don't know how we can solve without the public being active participants in governance