> It’s somewhat uncommon to have engineers known just iOS and Android, let alone a 3rd language / stack.
who stops reading a sentence in the middle?
I did not include Android or other stacks because I don't know about them (as I said, "not sure about other areas"). But for iOS it is not uncommon for developers to solely specialize in it, yet the comment claims it is uncommon. I wonder if you misread my comment or the one I replied to? Or perhaps the original comment is grammatically ambiguous.
So you need engineers that have this deep iOS experience, deep Android experience, and deep C++/rust experience. If you are a solo dev with this skillset then maybe it’s a good choice. But in a team / big company setting such an unconventional stack will always be a drag chute on your velocity in all stages of the project