Russia is steadily achieving their aims, they don't need to rapidly advance because they aren't trying to take all of Ukraine. They have the industrial capacity to be steady and thorough. Ukraine is putting up a fight, but can't actually last for much longer.
Secondly, regarding the profit motive, it will always result in less efficient investment. Industry is hollowed out, and can't be built overnight. Missiles, drones, etc cost far more to produce in the US than in Russia for comparable results.