I think that you are going to be surprised in the near future.
Just my opinion, but I think that we would see hundreds of different niches filled by different coins.
That's also my opinion of the "good" outcome of crypto, where you buy a crypto because you want to use it, and then forget about it. The thing that is needed for that are fluid decentralized exchanges (not big things, and not with all coins, but just linking a certain number of coins together, where essentially both parties put up some collateral (in one of the coins) to do the exchange, and then agree upon exchanging two other coins at agreed-upon exchange rate.
I see the future as coin to coin directly, without BTC being as an intermediary.
So you could have your own likable coin, and it could be traded on spot for the one that the merchant accepts with a minimal fee.
Sure, I didn't mean to say that BTC has to be the collateral. But I don't see how you can trade without locking in, the time of the trade, the collateral (worth more than both offers of the coins to be exchanged including fluctuations in exchange rate during that time), the time you settle on an exchange rate.