Which you have to carry around separately, which comes at a convenience cost and so you're more likely to just go for wireless ones (I know I have after the headphone jack wore out in my phone)

And also not charge at the same time unless you get a well shielded dac dongle with a usb female which also allows charging and supports thunderbolt, which is another piece of future e-waste that you'll have to carry around in addition to your phone and 3.5mm only dongle, as the unconnected wire will get caught on your hand if you try to use your phone

Your idea of a fix makes as much sense as apple calling selling you 90% of a new device fixing your device - let's not allow degenerate business practices just because a brand like to think of themselves as green and ethical, it's anti-consumer and anti-environment, no ifs, no buts.