Or another answer: terror tactics or just destroying anything big enough to group people, which, in my view, is the most likely possibility. It has been confirmed that there are a large number of schools across the country that have been destroyed, the "mistake" or the "false flag" options are just not realistic.
That's it and there are at least 2 reasons for that.
1. The west hit Russian citizens by banning certain goods and services so that these citizens put pressure on Putin, so he decided to do the same thing and put pressure on Zelensky by killing his people.
He thinks that civilian casualties may break the fighting spirit of the defenders.
2. Ukrainian soldiers are hiding in basements, they need to house wounded, store ammunition, missile launchers. More people killed in night bombings means less equipment lost the next day.
I am afraid this war if it does not end in a month or two, might turn into genocide on both sides.
Right now, Putin is warming up to the idea of bombing hospitals, kindergartens, churches, etc. where people are hiding.
Over time, he will give orders to wipe out whole cities as he did in Chechnya. He will not break Ukrainians unless he kills them all.
Ukrainians, as they progress to the offensive, might be less discriminate who they kill as well, driven by the desire to get revenge,
there is a risk that they will kill all civilians who support or supported Russia during this war.
That is the most likely end result of this war.
Ethnic cleansing protected by Russian nuclear weapons and weak NATO leaders.