kurama is quite good and there are situations where is better than six paths (with edo hashi is better than six paths since triggers by himself his 30 combo chase or as scarlettblue said he is perfectly matched with kushina habanero).

honestly speaking i don't consider madara better than kurama.

madara founder is easy to counter and sometimes may even be counterproductive (if the enemy benefits from stolen chakra).

kurama works in any situation.