I agree with Extinction Rebellion's basic demands and premises (look them up) but I think their methods of drawing attention lack focus and concentration. If you lump together all the issues that need fixing into one big stew, the odds are that none of them will be resolved or that it will take far too much time. What's needed is clear information and single-issue campaigns which the general public can easily participate in.
For example: give us a list of EXACTLY what products we could and should stop buying right now? Industries and governments refuse to change their planet-and-human-harming ways because they make so much money doing it. If their worldwide sales were suddenly to drop dramatically they would be forced to try alternatives.
Of course transport was held up and it took me three hours to get home from Oxford Street on Wednesday.