[dragonwriter]

Samsung's still making a flagship line with a stylistic after pretty much everyone else dropped smartphone styluses; and they brought back external SD cards, too, which a number of manufacturers (themselves included) dropped from flagship lines.

It's possible that dropping headphone jacks could become universal, but I don't see any reason to expect it's likely.

[2muchcoffeeman]

I can see wireless charging and waterproof devices becoming the norm.

Most people also buy headphones from popular brands rather than attempt to discern on sound quality.

I see quite a few AirPods and Bluetooth headphones these days. I don't think you can discount the possibility.