Well, no, not really. Top tier Indian cities like Bengaluru, Delhi and Mumbai are expensive and horribly dysfunctional when it comes to pollution, traffic, hygiene, dealing with government bureaucracy, etc. Having money insulates you from some but by no means all of this.

how are they expensive?

The parent literally mentions ‘the cheapest Indian cities’.

As others have said, even the richest cities have a swathe of issues which simply do not exist in the west (reasons for which are another discussion).

*looks at air pollution chart which is literally at 359 right this second (01:38)*

And are just as expensive as most nice places in the US

Have you ever travelled in Mumbai city trains during peak hour, I can assure you it's not nice. Look up videos on Youtube.