Imagine you had to choose only one altcoin for your bag. I can't decide between GRAM, LAW and Libra. The last one is the most questionable: it's popular because of FB but I heard it won't be profitable because of its features of stable coin. GRAM and LAW are great because of its technologies but they are not as popular as Libra. So...yeah that is my problem...And what is your choice?
Then look for the popular ones that are within the top 50 in the popular coinmarketcap or any popular exchange, I have never heard of these two before now, Libra coin that is even yet to be released has gained popularity more than some of these altcoins even though I do not think the hype will last long because it already has some discouraging features, but at least the team is still working hard to ensure that the project becomes popular and they are really getting the necessary attention for now.
I think the developers of these other projects are not very active, and there is no way a project can be completely successful if the developers are not active, aside the quality of the product itself. The best investment is to be placed on these coins that we know ourselves are popular enough to have the volume that will always boost the value.
It's a stable coin, right? So people look for so much stability that they always become destabilized. Good luck to that 'Libra'.