Yes, however there are several issues in having it in a dongle instead of inside the phone
You're needlessly converting to 'lightning protocol' and back. DAC will be lower quality than an internal one (because of size and power constraints and the fact that you need one internal and one external)
Generic dongles purchased from Amazon can be expected to have lower quality DAC's, but most people that want to cheap out on something that only costs 9 dollars probably aren't using good enough headphones or speakers to care.
In reality those constraints don't have any humanly discernable impact on the quality. Plus the part about the lightning protocol makes no sense whatsoever.
Here's an idea: Try blind testing 10 songs or so and see if you can figure out which one is played from the adapter and which one isn't. I bet you won't hear the difference.
I have an iPhone 7. In reality even that isn't an issue. You can keep the dongle attached to your headphones and it will stick safely to it.
I would really like to know how many people who find issue with the dongle have day-to-day experience with a headphone jack-less device. My bigger concern is that headphone jacks will vanish from headphones.
Because I have broken all my headphones and then my phone's audio jack I am trying out the dongly life. So far it hasn't been that bad, but I suspect that there will be situations in which I'll want to charge and have an audio device connected.
I dislike Apples love for dongles, but the headphone donglegate is mainly a constructed problem by people that just want to rage about something. Sure, it sucks that you can't use your headphones while charging but in reality I had this problem exactly once in a year of usage. There are actual problems with modern smartphones and iPhones in particular but the headphone jack is a ridiculously propped up issue.
> Yes it does, unless the port has an analog audio channel
Then you'd have an internal DAC.
Apple is extremely greedy with space, but a DAC/amp isn't large. The dongle has more available space.
The sound is digital before being converted either way, the "lighting protocol" won't hurt the quality unless they lossily compress, which I doubt.