Embryo is a vague term. What is actually frozen in IVF procedures is, at most, a blastocyst comprising a few hundred cells, which does not, from any  evidence-based perspective, have  any of the specific attributes that make us  human. Such unused embryos are not unique to IVF: between 40%-60% of fertilized eggs fail to implant.

This is an actual picture of five blastocysts from an IVF procedure. They are not extrauterine humans, they are clusters of barely differentiated cells.

IVF freezing procedures, via NYU Langone

Blastocyst definition, Cleveland Clinic
Implantation statistics, National Library of Medicine