Problem is that they still have thousands in storage, even if they are in bad condition, a tank is a tank, it still has its place in war. They still have ifvs and they still have artillery and the biggest indicator is that they are still capturing territory regardless of huge losses.
At the rate of 10-20 tanks a day, you are still looking at 300-150 days before they start running out of stored ones, not counting that they are manufacturing some amount monthly. But battle lines don’t lie. They are still moving in the wrong direction. I don’t like it and wish Ukraine could retake those territories but russians are far from wasted no matter how much we all wish that they were.
Its a very bad mistake to underestimate your opponent and assume that some magic wonder weapon will suddenly tip the scale of war. The only thing that will do this is increased supply of western arms and removal of the absolutely insane rules of not attacking russian territory.
F16 by themselves will not be enough, but they will help of course. Hopefully to lower the damage to infrastructure and hopefully to damage russian air force.