For more context, CET and friends don't actually act as a ROP mitigation in it of themselves. CET is a coarse forward edge CFI technique. For completeness, you must pair it with both some software function type assert (prevent argument type confusion by swapping function pointers, etc.) as well as a backwards edge CFI mitigation (such as secure a shadow stack for storing link addresses). Both are quite hard problems.

ARM's Pointer Authentication extension is an interesting alternative which does all of this in one feature by cryptographically signing pointers in memory.