Cardano still probably needs a year or 2 before it becomes significant and threaten ETH. Cardano is still untested by the public. Look at recently hacked or bugged ETH-based tokens recently, the problems with POS etc. Problems arises thru time and with Cardano, we're still unsure about it. Yes it may be technologically better than every other coin out there but we still need for it to stand the test of time and the public.