I think they’ll simply fall out of fashion, and gradually fade from view as people lose interest, like Plane Stupid and Occupy Wall Street. (Remember them?)
I’m not in favour of the powers-that-be quashing legitimate protest but I think XR’s brand of civil disobedience treads a very fine line — it has to be very carefully planned and messaged to not look like wilfully disruptive pranks with minimal point and diffused messaging.
The stuff with the tube trains a few years back was an example of protest action being ultimately self-harming and poorly considered.
I think, personally, the Black Lives Matter movement was far more effective and smart in its approach (although obviously driven by absolutely tragic circumstances).