a golden era is usually marked by improvements and achievements in architecture. thats propably why the mughals were considered the golden era. giving it an additional thought i think the last great mughal monument was that poor imitation of taj bib i muqbara in aurangabad built by aurangazebs son. the golden era ran parallel to the great mughal builders and then it stopped when they stopped building. similarly with the british. they tried to impress the masses they ruled with lutyens delhi. the cholas too had a great building history as you said " hit the skies" literally with towering temples.