Headphones were a solved problem. I had 20 years ago some high end IEM that i used back in the days on on so called mp3 players - those were pocket sized music players - and since apple released the airpods and bluetooth headphones were the new standard audio quality never recovered to the state we had two decades ago

It wasn't a solved issue because 3.5mm is too anemic to power modern ANC. Remember when headphones like QC15 had a single AAA battery to power that? Maybe it's not an important feature to everyone, but ANC is critical to my experience on long distance transportation.

Multipoint is also cool too. I like listening to music, taking a call, going to the toilet, and coming back to music all without doing anything.

If there's a silver lining to the last 15 years, it's that replaceable cables became a standard feature and that there are IEMs with direct USB C cables now. If/when Moondrop/KZ/Linsoul release IEMs that can be used like wireless earbuds with ANC, and can also connect and recharge via USB C, they can just take my money.

iPod Shuffle + Shure SE215 was the pinnacle of portable audio. The ritual of maintaining a separate playlist that would actually fit made it intentional. Allowing Spotify to slip into an infinite stream of slop is so easy these days.