Another hole can carry analogue audio? I think you're referring to a USB port when you say "another hole can do the same job", but obviously it can't carry analogue audio. You need an external DAC to convert the digital audio it can output, to analogue. (The phone already has an internal DAC so this is dumb)

And then of course you run into the issue of being unable to use it while the phone is charging because you have 1 port for 2 different jobs

Not all of us like the idea of wireless earphones, there are still many who prefer to spend good money on nice IEMs or headphones that don't have to be charged to work, rather than overly expensive, subpar wireless options that will inevitably turn into e-waste when the batteries can no longer hold a charge.

Not to mention the ubiquity of the 6.5mm/3.5mm jack, this is standard across every piece of music gear you can think of from synthesizers to electronic drum kits to guitars, pedals, and interfaces.

You certainly don't walk into a recording studio and find USB C ports to plug into