Every army uses unarmoured vehicles, the difference is that Ruzzia is using them to send the infantry on assault in open terrain. Just look for the videos, it is just suicidal.
I saw documentary about Americans moving in Afghanistan, they were moving about 20 meters per hour so they traveled 2 months between 2 villages because of
fear of IEDs and mines and civilians...obviously, Russians can't afford such approach and win a war like this