modern Russian commercial aircraft, why are they unpopular?

Gentlemen, and the one female poster here,

Please inform me to the challenges Russian commercial aviation industry has when facing the likes of Boeing, Airbus, Embraer, etc.

It seems that the Russians have made serious attempts to westernize their aircraft, yet it still seems unpopular despite being much cheaper.. what issues do they still have that remains unresolved? Is it noise levels? fuel fraction, maintenance? etc.