The AK-47 can be described as even older in that it combined major features of the US M-1 Garand and the German Sturmgewehr 44, iconic infantry weapons of WW II that were developed in the 1920s based on WW I experience. Supporting my larger point, the Russian arms industry has proved unable to produce an acceptable modern successor to the AK-47. In part, this may be because instead of seeking greater accuracy in their main infantry weapon, the Russians have put much effort into better sniper rifles and equipment.
Not related to AK and vastly superior. Tries to replace AK as a standard-issue rifle since 1971 and would probably succeed starting next year. As for a sniper's rifle it was actually Russia's weak point until just recently. SVD was not exactly a sniper rifle in international terms and the only more accurate alternative was Mosin. SVD has its pros but you certainly wouldn't like to use it in a sniper duel with someone who are more than 800 yards away and has a real sniper rifle.