Do you mean on-chain Bitcoin? Because transactions settle instantly on the Lightning Network (off-chain scaling solution). If you're talking about instant, on-chain transactions, then that's another subject. I hardly doubt they will ever become instant, especially when developers aren't going to allow it. You see, wait times are more of a feature than a bug. If BTC had zero confirmations, it would be less-secure (as it would increase the risk of a double-spend). At least, that's the way I see it. But I could be wrong.

Dash and similar coins have 0-conf transactions, partly because they use a concept called "masternodes" (which are nodes that provide specific functions to the Blockchain). Bitcoin Cash was going to get "Avalanche consensus" for zero-confirmation transactions, but the concept was ruled out by the community. The risk of doing this on Bitcoin is simply too high to bear. Better use the LN or another sidechain/L2 network if you really want to reduce wait times and save money on fees. But who knows? Maybe developers will make zero-confirmations a reality without compromising on the network security. One can only hope...