Someone at Pipeline clarified this for me. *Normally* to get bad inner hair cell damage you would have decimated your OHC first because almost everything preferably destroys OHC first. This is not because losing your IHC themselves makes you an cochlear implant candidate but rather because by the time they are significantly damaged (usually) your OHC are in the severe to profound range.Will McLean said on Reddit that a significant loss of OHCs means you need hearing aids, but a significant loss of IHCs means you need a cochlear implant. The participants in their trial were in hearing aid territory at the worst.
There are a few things, though, (like Cisplatin and high dose Azithromycin) that prefer to destroy IHC first though (edit: and it's hell from personal experience).