Aren’t these two very different products?
Earbuds (I’ve got Sony, Bose and Apple) are designed to take some pre-recorded and mixed sound and play it back with high fidelity. They can have multiple drivers for different bands to try to overcome the limitations of individual driver sizes.
These days the earbuds offer a microphone to pass through external audio to either the drivers, the Bluetooth connection or to be used to create “anti-noise” for noise cancellation.
Hearing aids on the other hand are designed to capture external sound, amplify specific frequency bands and pass this through to a tiny driver, that for most, is positioned with your ear canal. The batteries on these (I’ve only used the rechargeable) last significantly longer than most earbuds. Newer hearing aids now offer Bluetooth streaming and selective cancellation of external noise to allow other external noise (speech) to be amplified.
During my varied career I’ve used some discrete “earbuds” that had drivers of a similar size to the RIC receivers I use with my Phonak Lumity. There was no comparison in sound quality, the wired “earbuds” were sh… very poor quality compared to the Phonak receivers, but they were only designed to pass the spoken word from security radios, not provide the concert hall experience I expect from good quality music earbuds.
Different tools for different jobs (but these days with some blurring around the edges).