there are certain guarantees that some altcoin will be used as a means of payment in a persons daily life. But if you take into account the amount of altcoins on the cryptocurrency market that exists today, then most of these coins will leave the cryptocurrency market.
That's one of the reasons why a lot of them wouldn't make it because they are serving the same purpose. Most tokens that are not offering something unique apart from that of transaction, they are going to fail. When it comes to transaction a lot of people prefer to make use of Bitcoin. And when Libra gets released, Libra and Bitcoin will be the only coins that a lot of people would be using for transactions. Etheruem will also survive for smart contracts, then Ripple might be used by banks.
The only place I think altcoins has a future in is gambling, normal gambling but first and foremost e-betting.I can not see how it will take over from normal currency's in the world of buying or selling any other goods then btc.
For every altcoin that have been created there are purposes for all of them. I believe that in future they will be working towards that same purpose they were created for (which I believe they are doing now). But a lot of them are not going to make it, some are going to fail, because the purpose they were created for is something that wouldn't work out in crypto.