An article from the journal Lung[1] points out that Post-Viral Anosmia isn't exclusive to Covid[1]. It occurred with other viral infections, which is why you can have someone with a bunch of seemingly Covid-like symptoms but not have Covid. There's also this lit review[2] showing that destruction of the olfactory epithelium can occur in Parainfluenza virus, Human Coronavirus, and Rhinovirus.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8067782/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236684/