Ignoring the whole debate (you and I likely have similar views on Demidov)...
Yes, vastly better league. Check out SkA's roster.
The roster, scoring and goaltender statistics for the 2016-17 St. Petersburg SKA playing in the KHL.
www.hockeydb.com
Voynoc, Kovalchuk, Gusev, Shesterkin, Dadonov... That roster is beyond stacked.
The roster, scoring and goaltender statistics for the 2016-17 Magnitogorsk Metallurg playing in the KHL.
www.hockeydb.com
Mozyakin, Semin, Samsonov
So much talent in the league back then. Kaprisov was 21st in the league that year in scoring. Demidov is 15th right now.
The KHL was a much much better league back then.