The modern welfare state is the compromise reached by capitalist democracies to stave off communist revolutions. If you’re going to kill of the welfare part, be ready for the uprising part.
Compare that to when we still had revolutions, where it was very hard for government to know what is going on, and to find individuals without a huge effort.
I think revolutions have become next to impossible, unless it is lead by significant parts of the elite that controls at least part of the apparatus.
That's not even counting the far more sophisticated propaganda methods, so that many of the affected people won't even begin to target the actual culprits but are lead to chase shadows, or one another.
> You can’t kill/arrest 25% of your population.
Unnecessary.
> That is why Russia/China/etc are so scared to let any protests begin
Especially Russia's issue is that lots of the elites want change too. But you also underestimate that what the population also does not want is a repeat of 1990s chaos, and Russian weakness.