I believe the Russians are trying to destroy the Ukrainian army as their main goal.
If they launch a long-range offensive they will destroy much of Ukraine. When Russians take a city, all they get is rubble.
The Russians want a victory without bringing war to much of Ukraine, which would stir up far deeper and broader Ukrainian hatred of Russia.
The Russians I suspect have gone to manned aircraft because bigger explosive blasts are needed to knock out Ukrainian pillboxes.
Russia has been failing for over 2 years. Not a single major Ukrainian city taken by Russia since the invasion started.
“ The Russians want a victory without bringing war to much of Ukraine, which would stir up far deeper and broader Ukrainian hatred of Russia”
Would say they have failed at that already