It's probably more because they're pulled into this kicking and screaming, e.g by the EU, when for years they internally decided iMessage was the moat they'll never give up even a millimeter of.
If privacy was the primary motive trumping everything else they'd have ported it to android a decade ago to reduce sms use.
If privacy was the primary motive trumping everything else they'd have ported it to android a decade ago to reduce sms use.