get a glimpse...

Because of modern anti tank man portable missiles and rockets tanks are just big metal coffins. This issue only is compounded by the use of drones both carrying bombs and spotting for artillery. Stationary tanks sitting several kilometers from the front a also not safe as we have seen. A simple impact detonated grenade dropped through a hatch will set off munitions. So tanks have been moved way back and that brings us to aircraft. Anything in the air over front lines will not have a good time be cause of the copious amounts of AA on deck on both sides.

So what are they left with? Spotting drones and artillery. Modern tech has turned this war into a meat grinder where the drone pilot sits next to the gunner with helpful hints such as "250 meters south south west" walking the rounds into the target. Difference here is the guys aiming the gun are incompetent. Setups with a good team can hit the target in 3 rounds or less.

Also I'd like the add the fact that modern firearms are on the field. With everyone having a semi auto rifle sporting a fast changing 30 round mag and some sort of optic. any attack is met with overwhelming firepower from a position of cover backed by under barrel grenade launchers and spotting drone support (when available). This amounts to stupid losses on the attacking side.

This is why it's like WW1 again. They can't move forward but have to hold the position.