Are you a complete idiot? Russian best troops are (were) its professional soldiers (mercenaries). These ones failed pathetically to achieve the initial objectives (capture of Kiev/Kharkiv), and are now losing ground in the North-East (dramatically) and South (the latter losses not so dramatic tho). Mobilization means sending poorly trained cannon fodder to combat, somewhat reminiscent of Iran's human waves tactics in Iraq-Iran war.

"Militiamen" you're referring to were used in Donbass indeed and about half of them are dead or injured.They didn't achieve anything. Crucial for the initial Russian offensives were its peace time units (professional soldiers, like the US has them). They failed and Putin had to order a mobilization of random men with conscription experience, because the loss of man power alone became an issue. These are more numerous than professional soldiers, but way less qualified and even less motivated.