That's an awfully cynical perspective, but these terms evolved because they're useful. No one is forcing us to speak them (although they are forcing us to hear them.)

I would rather refer to affordances than to "user-facing touchpoints", because that's a more specific abstraction aimed at, specifically, interactive elements whereas "touchpoints" is, to me, vague; does it refer, also, to the merely visual aspects which "touch" our retinas?

"Friction" is a metaphor, and there's nothing wrong with that! I imagine that one monitoring a conversion funnel would naturally ask "what's causing the members of this cohort to drop out of the flow?" Well, it's friction that challenges spatial progress, and spatial metaphors make good use of some underused cognitive hardware.

"Increase stickiness... but also keep it lean", though is, at worst, an oxymoron and, at best, lazy along the lines of "... just make it good and not bad."