Why did the city eminent domain the buildings? To keep them from being torn down?

yes

https://www.wgrz.com/article/news/local/buffalo-cobblestone-district-eminent-domain-case-appellate-ruling/71-2918c9fb-859b-4284-8537-bab0961f8b69

March 16, 2024

BUFFALO, N.Y. — An appellate court has ruled in favor of the City of Buffalo in an eminent domain case.

Mayor Byron Brown's administration said it began the process on 110 and 118 South Park Avenue to protect the property from being torn down.

Now the city is awaiting a decision from an Erie County judge on whether the current owner has the right to demolish the buildings.

"The Brown Administration commenced an eminent domain proceeding to acquire 110-118 South Park to protect the property from further blight, deterioration and to enable redevelopment," the city said.

The two buildings are some of the oldest in the City of Buffalo, dating back to the 1852 and 1869 respectively.

I'd put money on someone trying just to preserve historic buildings.