Asus zenfone 6 E:failed to mount/ cache Phone stucks on boot loading.

wipe data/factory reset  gives 
E:failed to mount/ cache error

wipe cache partition 
also fails.

abd sideload also give
E:failed to mount/ cache
Can't open vs..

Many same post suggest TWRP but i don't have it. Did not understand how to install it on a phone can't open.

Many more says EMMC chip is dead. I hope it is not. I know it is very likely but i want to try other options first if i can.
I think EMMC chip is dead. only fastboot commands working. 

Sometimes you need to accept inevitable.