obviously kaguya s/t jutsu takes much more chakra than kamui
kaguya whose chakra is bigger than jiubi’s ,is worried about her chakra after using her s/t just few times
while obito clearly with hashirama dna was spamming kamui when he fought in the war
some people think obito needs much chakra too because he needed sakura help.but that is (as obito himself said )because he is going to teleport to another dimension that isnt his own one ,but when he teleports to his own dimension ,he can spam that
in terms of power ,i think both of them is so powerful jutsu but i prefer kamui since it can make you intangible and make you able to rip off your enemy’s head instantly (long range kamui)while kaguya’s s/t jutsu enables her to teleport the enemy to another dimension instantly with no connection ,and enables her to teleport behind the enemy and drag him and so does short range kamui ,
so i think kamui has the intangibility over kaguya’s s/t jutsu
having 5 or 6 dimensions doesnt make difference ,i think