Many altcoins attempt to solve the confirmation time problem. Litecoin is an early fork of Bitcoin that reduces the target block time to 2.5 minutes (probably still too slow for your coffee purchase). One that I see as having a lot of promise for retail purchasing is Dash[1]. They claim 1-second confirmations with InstantSend. I'm intrigued by the masternode network because it seems like the best compromise I've seen for gaining fast confirmations while maintaining most of the distributed and decentralized aspects of a good cryptocurrency.

Bitcoin is the largest and most prevalent, so it has become the currency most often used to exchange to fiat. Usually the transaction fees are still mostly negligible because these are larger transactions than the faster altcoins when they're used to make purchases.

[1] https://www.dash.org/

Though I feel like a lot of BTCers are not interested in this, payment networks based on top of BTC would be very interesting.

Essentially no barrier to entry, and some federation could happen.

Of course, what you end up doing is creating banks, but hey they're not regulated by the government if you are behind 5 proxies? "Hobbyist bankers" might be fun.

The ultimate frustration of bitcoin is that it can occupy the entire range of decentralization, but the community compares everything to the logical limits of "the Federal Reserve will defeat math and generate BTC" and "I don't even have to trust my own computer to do this transaction!".

Eth confirmation is on the order of seconds: https://etherscan.io/chart/blocktime