Today that role (strongly discouraging grouped formations) has been occupied by drones.

The current UA/RU front is a 30km deep kill zone crossed by FPV craft (and discarded optic fibre cables) in which the largest effective group size might be four or so soldiers. Tanks are all but useless as sitting ducks.

Reuters made a surprisingly good infographic / interactive feature on this this past July:

<https://www.reuters.com/graphics/UKRAINE-CRISIS/KILL-ZONE/zn...>