Why buy bitcoin?  I don't know, it's a good investment that can also be used as money if need be, and I have purchased stuff with it in the past.

I am not a 'Libra-phobe' but I can't understand what all the hype is about it besides it being facebook's baby, their foray into the world of crypto.  Their user base alone should ensure that it sees a lot of use...if it gets launched, and that's a very large if.  Better still would be that Libra leads its owners to gain an interest in other cryptos, chiefly bitcoin.  I have some hopes that it will achieve that, but again only if Libra makes it thru the regulators.