I appreciate the optimism (and do think there's some room for efficiency improvements!), but each step is a little more complicated than that. a true audiometric room/booth to do the testing (eg fully soundproof) in is very rarely found outside of audiologist offices or specialized academic spaces, for starters, and I do believe those are required for paperwork (whether it be insurance related part of the process to getting the right device fitted).

then there's also additional complications like types of hearing loss impacting calibration - some people react very negatively to higher (or lower) frequencies than others do, to the point facial stimulation can happen, and some people just have a frankly tricky profile that requires a trained audiologist on hand to work with them through several sessions, if not outright yearly on top of that, since the nerves and brain output can change by itself.

(source: have a cochlear implant, been doing the described experience since I was ~ 3yrs old.)