If you also consider examples of North Korea, Iran, Venezuela, Cuba and many other dictatorships, you'll see that isolation doesn't really correlate with regime change.
Even if isolation does not necessarily correlate with regime change that is still something that in the end gets decided within the country, not outside of it. After all, regime change is exactly what Putin was after in Ukraine so that would seem to be fair turnabout.
So out of solidarity, russian users could move their domain names out and leave it as is.
Not to spoil your evening but it is so far perfectly imaginable, though it very well could become unimaginable soon.
Edit: grammar
The 'lets start with a small nuke' aka tit-for-tat scenario has been wargamed literally to death: it ends with total annihilation.
Now, domain names going away won't cause deaths, but then again they won't cause regime change.
Personally I think the tax bit is thin, but I totally understand the pressure on their employees and that that does not feel right. They are waiting for the next missile impact while at the same time they are working to keep the websites of their enemy up and running, that's not something you should want or expect.
But in the absence of any ability to hurt said mortal enemy, they seem to have picked a target by association that is within their reach, so as to hurt something related to the enemy.
I understand why this is happening, but I don't see it as justifiable.
In the country where the problem originates or in some other country?
And yes, people will suffer, that's what happens when one country invades their neighbor in an unprovoked attack. You're placing blame in the wrong place here.