Re: "And what about being offline and not risking to die in a building that caught fire?"
> ie is cladding a cheap alternative to getting rid of eyesores or is it actually useful as external insulation?
Yes, it does have a benefit as insulation - both heating in Winter and cooling in Summer as it is more reflective than the original pebble-dash on concrete. Putting it over 'rockwool' [1] would provide even more insulation, as has been done to some other towers.
[1] There is both 'rockwool' and 'rockwall' available and the pronunciation of various UK newsreaders is not clear enough to be sure which they are referring to.
My gut feel is that the 'rockwool' towers are going to be just as fire prone as Grenfell though, *if* there are also polyethylene panels fitted over the top.
I expect the outcome of the official inquiry will be to recommend that similar cladding on other towers be removed/replaced but not to insist on retro-fitting of sprinklers. (It is already mandatory for new build towers to have sprinklers.)