Nobody is going to "attack" Russia. Out of those sixteen neighbors there is exactly one, China, which could even begin to contemplate taking on Russia in a land war. (And they still would not, because nukes.)

On the other hand, China could try and strongarm Russia into concessions (no idea which ones) while politely performing military exercises on the other side of an undefended border.

Similarly, if NATO starts politely performing military exercises near any of the other borders of Russia, Russia needs to be able to demonstrate that they have an army guarding said border.

I'm somewhat doubtful that Russia is keeping their best equipment in reserve in case checks notes Georgia or Finland invade them.

While there has been some drunken bar-talk about retaking Karelia and re-establishing the pre-WW2 borders, It's not likely Finland will attack Russia.

It's more likely the russians are a) incompetent, or b) saving the bulk of the air force for a potential escalation of the current hostilities. One does not have to exclude the other.