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.
A master plan to make more money selling a cable than a port on an already bulky phone?
Ah yes the 3.5mm port, known for its bulk. Perhaps we should remove cameras as they have actually bulked out phones in recent years.
If I had the option I would have chosen a smaller camera module and included an audio jack. I genuinely think they choose to not include it as a compromise, rather than to sell a cable you can get cheap elsewhere.