As others have said here: it’s pretty much a battle of closed system (Apple) vs the world (Android-based cell phones). Altho the Android phones (Samsung being my own brand) are 5 times more popular on a global scale, that doesn’t mean that software companies are willing to create Android-based apps to help hearing impaired users! We are still a sliver of the total market.
In that respect, I have to hand it to Apple to have jumped on the wagon really early, developing a range of Apple-compatible apps for us hearing impaired users. Even so, I’d prefer an OPEN system, not based on a singular hardware platform. I just get a creepy feeling that Apple wants to control ALL forms of communication: written, spoken, et al, store them on a cloud, make it useful for the NSA, even hackable; slice and dice data for marketing spam …
For now I am sticking with my Android-friendly Phonak Audeo B-Direct aids that work beautifully with my Android-based Samsung 6S Global in addition to my MacBook Pro running OS High Sierra. Um, which reminds me: y’all read about the SUPER bug that enabled root superuser access to Macs? Fix it now!