[anm]

^^

1. not sure what you mean when you say "not to be seen out of Moscow", plenty of supertalls are being built all over the world
Oh, I guess you mean not Europe.

2. the reasons for building supertalls in Moscow are the same as anywhere else in the world - they are a statement of might and power, they attract attention, become focal point of a skyline , bring visibility to the city and occupants of the building; become iconic images of the place, i.e. they satisfy ego