However there is a case to be made that if the systemic dose is adequate, this should restore the health of ALL estrogen responsive tissues, as vaginal atrophy usually only occurs in the setting of very low systemic estrogen.
I personally believe that the ongoing presence of vaginal atrophy should prompt a review of the systemic dose, particularly if the treatment is indicated for osteoporosis prevention or health maintenance and especially if that woman is young or has POI.
Replacement in POI that is so low it needs to be propped up with vaginal estrogen should be a never event, as their age matched peers with healthy ovarian function don't have urogenital atrophy.
However there are women who cannot access a therapeutic dose, others who make an informed choice not to increase their dose, and some who are limited by side effects.
Therefore nobody who wishes to use vaginal estrogen in addition to systemic replacement should be denied it on the basis that it is "too much" estrogen. This is incorrect, especially given the absorption of topical vaginal estrogen is so negligible that it is considered safe in active breast cancer.
There may be some situations in which healthcare systems or insurance based plans won't fund both, but this is a cost issue not a clinical safety issue.