Ukraine has been targeting Russia's radar and early warning capabilities, allowing them to fly drones into occupied territory and into Russia proper to hit high value military targets, refineries, factories and more.

The A50 was in part to coordinate airstrikes on the front, and in part to fill the radar gap.

Now the gap needs re-filling... Again...

In the mean time, refineries and fuel depots burn, airfields get hit, ships get sunk. It's getting harder every day.. for both sides.. but the loss rate for Russia is only sustainable as long as their enormous reserves last... But they are dwindling...

This is the attritional warfare Zalushni was talking about. It's like 2 boxers beating the crap out of each other untill one has had enough, can't raise his arms anymore, or goes KO. And neither is KO just yet.