@cybertailor they have to, otherwise they can/will be sanctioned, which would hurt the service for everyone.
This doesn't mean I agree, I'm just explaining why this is happening and why it's pointless being angry with Mozilla for it.
Mozilla, without any notice, makes such extensions (and only them!) unavailable in Russia.
They blocked tools to circumvent sanctions, for the sanction country... like, you don't get to ignore the wider context here just because it fits your narrative.
If you wish to be angry at someone, be angry at Putin and his cohort of yes-men for starting the war that caused the sanctions to begin with, not Mozilla for following the law.
@iamada what's more likely is that Mozilla received a letter from Roskomnadzor saying something like "remove these extensions or else we block the whole addons.mozilla.org".
In this case, Mozilla followed the law, but it was Russian law banning censorship circumvention technologies.