The general point on air power is a real thing, but I don't think we can directly conclude that bombing will always harden civilian resolve. It very much depends on the population's pain tolerance.

In Vietnam when the NVA attacked a chain of US military bases simultaneously they lost every single battle, by a huge margin. It wasn't even close, the USA suffered about a quarter as many casualties, yet it broke the back of US commitment to the war. That's because the NVA could take 110k casualties and maintain their commitment, but for the USA about 25k casualties was intolerable.

On the battlefield Russia is losing masses of troops, but as Vlad Vexler points out, because these are mostly essentially paid mercenaries this is seen by the Russian population as a transactional risk they are taking.

Direct pain for the general civilian population is another matter. Most Russians seem oblivious to the fact they are actually in a war with a neighbouring country. They seem utterly bewildered by the fact Ukraine is even attacking Russia at all, it doesn't seem to make any sense to them. This is why the government has done everything they can to avoid resorting to a wave of conscription, they want the whole thing to seem very distant and abstract.

I think the pain tolerance of the Russian population over this is minimal, bringing it home to them is really important. The only thing is they have no accessible ways to translate that into political action, but if they are ever going to wake up, prods like this play an important role IMHO.