As a recent XS buyer (upgrade from iPhone 7) my strategy is just going to be waiting 2 or more upgrade cycles before buying again. I still value the ecosystem and trust Apple with my data more than anyone else, especially in the case of iMessage.

I don't think I'll miss anything serious from skipping upgrade cycles. I'm not much of a camera user and Face ID is meh to me so From iPhone 6 to XS I've barely seen any improvements I care about other than water resistance which was a 6 -> 7 upgrade.