Simple answer is yes. Take out kohli and Rohit and India will no longer be the power house it is.
Smith and warner are the backbone of the side. However I don’t think it’s their exclusion that’s solely responsible for the passive decline.
I think the dressing room culture and aura has been massively hurt. I feel things are not the way they used to be. Australia don’t seem to be united as one as they normally are. They are extremely low on confidence. Australia is a bully cricketing nation. They love to dish it out. However when on their own and without their boys they are sheep. That’s how things are now. The dressing room everyone is feeling sorry for them selves and are isolated and confidence ain’t their. Like bullies when they are groups they become high and mighty again as the artificial confidence returns.
Same will happen when smith and warner return. They would be the lions coming home ready to lead. The squad will be full of confidence again as their back home is back and so would the performances. Of course this is all pseudo science. However the mind is a mysterious organ. The placebo effect is strong and scientifically proven. Watch Australia roar again when the messiahs return.