I swear, every damned article trying to talk about the Russian military strategy is approaching this with babies first RTS levels of thinking.
"Russia have two million troop, why Russia no use two million troop?" - Saturating an area with your guys just means saturating an area with targets for your enemy to shoot, for little benefit. Russia has no need to commit to big bloody field battles right now, they squarely hold the initiative and maneuver advantage. This isn't WW2 where large formations had to be roughly guided into each other due to lack of low level communications equipment/technology. Russia is currently presenting an excellent example of early post cold war ideas, with highly mobile forces avoiding engagement and surrounding areas of high resistance to cut them off, taking advantage of advanced communications to coordinate those moves.
"Russia claim air superiority but Ukrainian planes still fly?" - Because air superiority does not mean you've destroyed every single air associated threat - it means your air forces can operate with minimal enemy intervention while being able to guarantee complete intervention on your enemies air operations. Ukraine can still launch jets - Russia is just completely capable of engaging any of those sorties as they see fit. Which is why high density targets like the armor convoy didn't get struck, launching would be guaranteed air casualties for the Ukrainians, and being outnumbered from multiple angles in BVR air combat is a death sentence.
Journalism is dead, and ego killed it.