> One is they trap lint internally,

I've owned my current phone for ~4 years, and the first port to stop working — due to lint — was the USB port, not the audio port.

> Lint is very difficult to remove from the outside the connector.

Removing lint from a 3.5mm audio port is going to be vastly easier than removing it from a USB port (which is completely possible). The entrance is much wider, and you don't have to worry about damaging the connector thing that USB has in the middle, as it doesn't exist. I've even removed a silica gel ball (which are apparently about 3.5mm wide …) from an audio port (and needed a paper clip to crush it first). I'd not want to try the same thing on a digital USB or lightning port …