that is pure Russian propaganda. Most of the videos of destroyed armor in cities is Russian armor - i.e. it is Russian armor hides in cities (yet it doesn't help them against Molotov cocktails and RPG and high-precision strikes https://youtu.be/D5WoCUqNWIs?t=13).
Russian airforce and artillery indiscriminately bomb and shell Ukrainian cities using unguided bombs and unguided missiles (from "Grad" and "Smerch" systems), and among the huge amount of videos of Ukrainian cities destruction by Russians there is no videos with Ukrainian armor inside destruction - ie. Russians attack residential areas without any Ukrainian hardware there.
On March 5 Ukrainians shot down such a Su-34 when it was bombing Chernigov and captured the pilot. The pilot confessed to the order of bombing the city (https://www.youtube.com/watch?v=BkszHkNoQNo, https://www.youtube.com/watch?v=PWrxX_gpNjM). That pilot has been doing similar unguided bombing of Aleppo 6 years ago (https://www.unian.net/war/bombil-mirnyy-gorod-letchika-so-sb...) for which he was celebrated by Putin and Assad.
Russian bombing of cities is done to force Ukrainians out. That is ethnical cleansing, a part of the announced by Putin destruction of Ukrainian ethnical and national identity.
>Air supremacy is already achieved (almost all Ukrainian war planes and strike drones have been shot down), so it does not make much sense to patrol the air space too much.
that just doesn't make sense, especially given how many Russian ground hardware is being lost to drone fire and to drone guided fire.