Not the best analogy. The glue factory was a thing while horses were a primary tool for transport and heavy labour. And horses were treated appallingly. Now that they’ve been made redundant, living standards for horses have improved dramatically and the glue factory is long gone (though their population has also reduced significantly).
We can only hope for a similar outcome for ourselves.
The outcome for the horses is less than ideal. The population was reduced by 33x. Sure they're treated better now as their leisure animals or sport animals. But I do not wish for their outcome on humanity.