Is there any altcoin that has so much potential as use case in our lives?
It seems that even major altcoin like Ethereum still struggles with securing stores to be used...
There is no other coins apart from the Ethereum you have mentioned. I have never seen any other coins being used for transaction in any case, not even in online stores. Ethereum is the only altcoins that I have seen a few times, the majority are using Bitcoin.
I have also made use of Ethereum and I'm currently using it now for transaction because that's what my business partners uses for transaction, sometimes they switch to Bitcoin. If Libra should be released there is probably going to be huge adoption for it and the way I see it it's going to be on par with Bitcoin when it comes to use case.