I suspect the real answer is that between decoys and Russian intel agencies hiding him, and his grip on power that currently means he's going to be in range of useful air defence and a good bunker even if it's literally the last system Russia has left, they likely literally cannot at the present time.
(Not that it changes what I just wrote, but IIRC most of the Russian personel losses are short-range (20 km) antipersonel drones, the long-range stuff is currently targetting materiel, logistics, and whatever you count oil as, in so doing they only incidentally hit people).
I can think of many possible reasons.
I suspect the real answer is that between decoys and Russian intel agencies hiding him, and his grip on power that currently means he's going to be in range of useful air defence and a good bunker even if it's literally the last system Russia has left, they likely literally cannot at the present time.
(Not that it changes what I just wrote, but IIRC most of the Russian personel losses are short-range (20 km) antipersonel drones, the long-range stuff is currently targetting materiel, logistics, and whatever you count oil as, in so doing they only incidentally hit people).