Why do you think they charge in the first palce?
It's paid for with state and federal grants, university (OSU) contribution, as well as a utility fee.
As for technology, they use bluetooth low energy to connect to the smart phone, which works really well, with the caveat that the range is quite low and if it is in the pocket and you are moving around, media sound will often disrupt or desync intermittently. On the plus side, they last well over a day even with media use (WIdex says they last 37 hours without bluetooth use and that checks out). The case provides charge for about a week, and has wireless and usb-c charging.
They are quite pricey, but there are several options (110, 220, 330, 440), and the 220 were more than enough for me. The app has several modes, including directional focus mode, and you can define your own. I sometimes use a different mode for listening to concert music, that disables most filters such as volume protection.
I am wearing them for 9 months now, and there was no situation (concerts, traveling, work, sports, etc) were they gave me any issues whatsoever.
For one, unless you use Med-El's Rondo processeor, you're going to have a thin cable connecting your processor to the coil. Taking off your CIs and putting them back on (as one does every day) is going to put stress on the cable. Sometimes the cable frays and you find that out with sound cutting in and out. There's nothing you can do until the manufacturer sends you a replacement cable in exchange for your frayed one. If you want a backup, be ready to shell out $250 for each cable.
Another UX issue is that processors depend on gravity to stay on your ears. Since there's no earmold to anchor to, processors can easily be jostled off and left hanging precariously. Wearing hearing aids, I never had to worry that my hearing devices would fall off if I rode my bike on a bumpy road. Also with cochlear implants, high-intensity interval training requires some kind of hat or bandana to make sure that the processors don't fly out.
Battery life is another disappointment. Rechargeable batteries don't last a full day. If I put them in at 6:30a, they'll last until about 4:30p. With disposable zinc air batteries, I can squeeze out about a day and a half, but then I'm having to dispose batteries. And while I can track processor battery levels with the rechargeable batteries on my phone, disposable batteries are opaque to the app.
One new thing that would be useful in terms of UX would be an configurable indicator, e.g., a blinking LED, signaling that audio streaming is occurring. It's awkward to find oneself in a conversation that already started and having to excuse oneself to turn off the stream.
Don't get me wrong, I'm glad I have my cochlear implants, but they're way behind hearing aids in terms of UX.
UX for a lot of assistive technology is iffy at best. Repeating some of the comments others have made, I'd love it if Apple would make a full on hearing aid that "just worked". Or someone would do a good AI integration that could notify you of things you probably should focus on - like someone trying to get your attention, or emergency vehicle sirens, etc.
Marketing too. But it's nice to see some vendors starting to actually make their devices visible and fun. HAs are a bit like glasses ages ago, when it was kind of this shame thing to get teased about when you were 8 years old. Selling them as "discrete" and with colors designed to match your skin or your hair is just continuing that perception of them being something you should hide.