Is flower and shrubs growing solution for pure air in the city?
Well, of course they will be helpful, but the larger the plant the more oxygen produced and the cleaner the air. I don’t see how growing trees has a detrimental effect unless you mean on the development of new cities, roads, and neighborhoods. If this is the case then I guess some priorities are a little messed up and the growing of flowers and shrubs may be your best option.
