Our data on the 1889-90 pandemic is pretty thin. We don't have any reliable records on deaths in poorer countries so the error bars are quite wide.

A lower infection fatality rate in that previous pandemic is not at all surprising. Back in 1889 elderly people made up a much lower fraction of the population. And there was a lower rate of co-morbid conditions such as obesity, diabetes, and hypertension.

Sure, there have been a lot of Flu pandemics with lower case fatality rates as well. Prior to this pandemic, they had actually narrowed down the flu subtype:

"the reanalysis of seroarcheological data suggested Influenza A subtype H3 (possibly the H3N8 subtype) as a more likely cause for the 1889–1890 pandemic"

There was no thoughts that it was Coronavirus related before this pandemic.

edit: Interestingly though, the 1889-90 pandemic was thought to have originated in Bukhara, part of the Russian empire at the time, which has been historically a cattle raising area. H3N8 is Equine influenza virus, where as HCoV-OC43 was a Bovine coronavirus.