How can you be sure they don’t convince anyone? I’m not sure, but I think you made that up - as it matches what you feel
Do you think it convinced the motorists who have beaten them and dragged them off the road by their hair? Or the people responsible for the preservation of Stone Henge? Or the wealthy people whose jets they painted? I can’t prove a negative, of course, or religion would be gone but you may be right, they may have convinced someone.
At least they tried, instead of just discussing the form of protest on the internet. History will prove them right.
And I built a straw bale house 20 years ago that saves 75% on heating and cooling over my next door neighbours smaller house. I am making a real difference by making personal changes instead of trying to ram my moral superiority down other people’s throats.