Even if you don't want to base your opinion on data, just check how is life in Mariupol today[0][1]. I don't see mass killings or rapes, just people living their lives.
It's war, obviously people died during the battle for Mariupol, but people aren't dying anymore, in fact Russia has spent huge amounts of money to rebuild the city and "win over the hearts and minds" of the locals.
Don't take my word for granted, read the BBC[0].
If nothing this should be an argument to cease all hostilities as soon as possible, rather than making countless more people die in a contest over who will rule a specific piece of land.
Now, do you have any proof of mass killings and rapes going on now?
The Germans made some lovely newsreels about the places they "liberated" that you'd probably find to be equally inspiring.
I think it would be a very interesting experiment.