I wonder why we don't get biennial [S] release years at all anymore. At this point, more of the iPhone's lifetime has been without S releases than with, but the

I wonder why we don't get biennial [S] release years at all anymore. At this point, more of the iPhone's lifetime has been without S releases than with, but they could probably sliped back into that cadence and no one would've complained. 16 -> 16s -> (17 + 16s /w discount) -> 17s -> (18 + 17s /w discount) -> ... I'd even say that the Pro could be it's own line. The unibody aluminium and tweaked looked would've been a good starting point for "iPhone Pro". (then iPhone Pro 2, 3, 4...) That could free them from having to segment the market for every single iPhone release by "pro" features, since the new pro in theory might only ever need a biennial release.