I think most enemy infantry zones will be rich in ATGM. We do not need tanks anyways when there is no presence of enemy infantry. With tanks, enemy gets a clearly visible, slow moving target which can be taken out easily.
Terrain, as you rightly said, are important. Different terrains will require different strategies.
But even if we take example of dense forest, it would be easier to operate drone than a tank. Tank will find no movement except on roads (where they can be targeted) while drones flying all over the forest can identify hiding enemies through heat signatures.
ATGMs have its own limitations. ATGMs are expensive bits of weapon that needs sperate training for effectively using them. You just have to use tanks more carefully in combat.
Even MANPADs are present in UKR in numbers. When it did some grievous damage to Russkie chopper fleet, once the Russian leadership woke up from their slumber and changed tactics, the loss of choppers to MANPADs have come down.
So, tanks will need to change tactics and adapt to new war scenarios. It cannot go in a theatre alone or minimum screening as a boss it used to. It will have to be used in battles where it is accompanied by good forward screening by drones counter anti-tank systems like BMPT Terminator and even drones specialised in taking out enemy ATGM teams. Tanks are important not only for the protection it has, but mainly because of the direct mobile fire power it brings. A 125mm HE shell directly fired at an enemy position can do what a drone dropping a bomb wont be able to do.
The Russkies screwed up at many level in the initial thrust. The military planners sucked. I don't know if any war ever saw a armoured column stuck in a 60 KM long traffic jam in the history of warfare!
But, they have learned and evolved. The losses in armour too have come down. Given the nmbers of ATGMs being recovered from UKRpositions by Russians and DPR militias, the reduced number of losses is not because the UKR has run out of ATGMs.
