The question is.....are the helicopters obsolete too? Obviously they are still useful if you fight against an enemy in a third world country. But not if you fight in a first or second world country where they have access to weapons like Stingers that can take out helicopters.
In GW2 a company of Apache gunships got decimated when they were sent unsupported over a defended area. Seems to me that the Russians are misusing their rotary wing assets just as we did in that instance.
Helicopters will continue to deliver airborne infantry and provide support for awhile. And even anti-aircraft support. An experiment in the 70s put attack helicopters against fighters. Surprisingly the helicopters cleaned house.