Do you think big companies could choose another one for payment unit instead of BTC?
price being high has nothing to do with the decision of any company about accepting something. it is like saying $1 billion dollar is so high so companies should stop accepting dollar! you know there is smaller amounts than $1 billion dollar like $1 or 1 cent. bitcoin also has smaller amounts such as 1 satoshi!
the fact that people choose to hold bitcoin rather than spending it has two reasons: the rising price which has nothing to do with how much it is. it can be $10 and rising to $20 (100% rise) and they still HODL it.
and also the high fees.
and nobody would choose BCH or BTG or even the shittiest of all BCD for a substitute since they are worse than bitcoin. if they want, they would choose something better. and something better is not among the top 10 altcoins i assure you.