I'm not sure what it actually means. For instance Apple Pay is probably not supposed to replace your actual credit card, but if you can live your life without ever using the physical one, that's just legalese.
If it really doesn't do much (i.e. only help to pass TSA lines), then perhaps it should be called something else. If it effectively can act as a passport in 80%+ more situations, "not a replacement for xxxx" will just be legalese for most users.
Yeah I purely care about whether or not this will get me through TSA. I'm against Apple Pay and all that, but I really don't want to carry (=risk losing) my physical passport just for domestic travel.
If it really doesn't do much (i.e. only help to pass TSA lines), then perhaps it should be called something else. If it effectively can act as a passport in 80%+ more situations, "not a replacement for xxxx" will just be legalese for most users.