Russia are working hard for the renewal of their vehicules. A lot have been destroyed and damaged in Ukraine but they are replaced with better equiped ones. Improved proven system are way faster to build and easier to maintain.
But still waiting for the arrival of mass produced active drones protection.
As long as the base metal hull remains intact, both sides can pull the wrecks, completely strip them down, then rebuild them with new, salvaged or cannibalized parts, sometimes even 3D printed parts.
Despite high numbers of kill claims from both sides that should have exhausted inventories, the equipment continues to persist even after four years of intense war. This leads me to believe there's plenty of recovering and rebuilding going on. Not too long ago, for example there was a footage of a destroyed Ukrainian BMP-2 being evacuated by a recovery vehicle. Looks wrecked but it might be deemed rebuildable, and end up fighting for the Russian side.
