You are missing the fact that lugging an adapter is not a realistic option. I lived the dongle life for almost two years. By the end the darn thing had started glitching on me and you could not buy replacements. I'm lucky it didn't damage the charging port...
Not that it matters, I still didn't have it with me half of the times it turned out I needed it.
I actually considered buying like 10 of them. Now we are talking about 100 USD of the crap and a MASSIVE and daily inconvenience just because the manufacturer decided to save a couple of cents. This shit is just ridiculous.
I have AirPods for meetings and music while walking, the normal Apple buds - now just backup in case I leave my AirPods behind, some Sony closed back monsters for shutting out noise while working in cafes and some nice open back Grados for music listening at home.
I hardly use the Sonys but if I do, I will just borrow the adaptor from my Apple buds in my laptop bag. For listening to my Grados I use an amp with a headphone socket.
If I wanted to plug them into my phone I would need the Apple lightning adapter and also one to the smaller headphone jack! This doesn’t bother me. If I want to do that, I’ll just do it.
I’ll even spend another £9 on an adapter to leave connected if I do it often enough.
None of this seems terrible to me and I’m not sure how unique this set of circumstances is. What are the tons of situations where this gets tricky?
1. Lugging your adapter just isn't an option. Stop. This should be enough reason. Seriously. Don't try to justify it in hindsight.
2. Since I had to constantly borrow my adapter from my regular headphones it happened that I forgot them connected to another headphones. So I often had my headphones with me but missing the adapter. Wasn't frustrating, promise.
3. I don't know when I'm gonna need it. I made a long trip by train and thought that some nice bluetooth noise cancelling phones would be nice. Well, at my destination we took a drive and I was asked to play some music. Ooops, no adapter.
4. At work my bluetooth headphones lost battery, no worries, you can still drive them with a headphone jack. Ooops, no adapter.
5. I dance, one day when arriving to practice the people responsible for it were running late. No worries, just connect your phone! Ooops, no adapter.
6. If your going social gathering with friends to a cottage you might not think to bring your headphones. But while there some music would be kind of nice. Ooops, no adapter.
Situations like that happens all the time, and it's nothing one thinks about because it's just a given that everything works. Well, was... So now I actually did bring my adapter even in cases when I didn't need my headphones. Which was another source of (2).
The above inconveniences all assume that it works as expected when you do have your adapter. But it doesn't. You can not charge and listen to music at the same time and while I love USB-C to bits it is way too clunky to be used while in your pocket. The connector did actually start to show signs of wear from having the adapter connected while walking. Luckily I had no issues charging my device but I actually don't know if data still worked.
Think about it, that alone is also completely unacceptable.
And that's all assuming that it would be kind of okay to even have an adapter at the end of your cord, even that just isn't.
Get into a friends car which only have aux input, try to connect to an older receiver, tv, boombox or computer speakers. I do this almost daily, so i have to loose several posibilities for the added convenience of what exactly?
Not that it matters, I still didn't have it with me half of the times it turned out I needed it.
I actually considered buying like 10 of them. Now we are talking about 100 USD of the crap and a MASSIVE and daily inconvenience just because the manufacturer decided to save a couple of cents. This shit is just ridiculous.