Khayal and Dhrupad are the two major forms. Numerous “lighter” forms exist such as Thumri, Kajri, Tappa etc. Now a Dhrupad singer does not usually specialise in Khayal and vice versa. And while a Khayal singer may include a Thumri in a concert, there have always been singers who specialise in Thumri-Dadra and sing nothing else.
Third, a variety of different forms exist in Hindustani music, but not everyone is singing them brilliantly. Also, access to these forms remains limited. I return to my old pet peeve, there is a lot more on the net in terms of quality Carnatic music… In sum, the variety exists in the North, but differently.