LIBRA will most definitely try to Monopolize the Industry and there is no doubt in that but you have to think from an Investor's point of view.

Have you ever seen an Investor who has all their Fingers in a Single Pie?
Investors love to Diversify their Portfolio so if they enter the Crypto Market they will most certainly Diversify into other Cryptos as well.

As for LIBRA's success, we just have to wait and see it for ourself.