> Invested in quality audio equipment that they'd like like to continue using without a crappy dongle
They likely can get better audio with a dongle.
All audio sources on a phone are digital. When you use headphones with a built-in jack the analog outcomes comes via a DAC and amplifier built into the phone.
When you use a Lightning or USB-C dongle the DAC and amplifier are in the dongle.
If the former case you are forever limited to the quality of the DAC and amplifier built into the phone. In the latter case there are higher end options available.
In 2024, most built-in DACs on a phone costing more than $200 new (so not picking bottom-barrel parts) is going to be of similar quality from a human-perception perspective. If anything a cheap dongle is more likely to have a PoS DAC. And even still, a lot of DACs will suffice for like an audio cast & provide a lot of convenience, but that wouldn’t prevent you from using a dongle DAC for a difference audio setting--even with the dongle’s downsides.
They likely can get better audio with a dongle.
All audio sources on a phone are digital. When you use headphones with a built-in jack the analog outcomes comes via a DAC and amplifier built into the phone.
When you use a Lightning or USB-C dongle the DAC and amplifier are in the dongle.
If the former case you are forever limited to the quality of the DAC and amplifier built into the phone. In the latter case there are higher end options available.