Nice theory but that is not what is happening on the ground. The Russians no longer have the unlimited supplies of artillery that they enjoyed at the start of the war. There have been many complaints by Russian soldiers that they have had inadequate artillery support. Videos show them repeatedly attacking across open fields with little support and suffering devastating casualties. No, this is not just the artillery duel with the Russian infantry advancing latter to mop up the Ukrainian positions that you think it is.
The Russians no longer have the unlimited supplies of artillery that they enjoyed at the start of the war.
I expect you to soon cop an insanity plea. Russia just took 110 km2 in one day. The Ukrainian defenses are collapsing.