With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
I agree modern phones have the horsepower to do a full on audio production; how does a 3.5mm jack help in this setup that a multi-bus USB-C DAC or mixer can’t do a better job than a driver that’s confined to 5mm of space?