Bitcoin as currency vs store of value

So to keep this short, I tried educating my grandfather on how bitcoin works and why people think it's worth something. Explaining how easy it is to transfer, how rare it is etc.. He kept asking me if he can buy some and then go buy a house or groceries, I said that depending on the seller of the house it could be possible or exchange your bitcoin for fiat.

I don't personally believe it will be a currency in the future but maybe I'll be proven wrong but I do believe it's equivalent or better than gold as a store of wealth and that's what I explained to him.

-Easy to buy/sell in seconds. -Don't have to worry about storing something physical. -Smaller market cap so better growth opportunities -After 21 million bitcoins are mined no more can be. -I also read that there is an astroid that contains so much gold that it could collapse our gold market if we ever got our hands on it.