This seems to date a looooooog way back. When Flarum switched from EmbedJS to Mithril 6 years ago, comments-o
from FontAwesome4 was used. When we migrated to FontAwesome5 3 years ago, comments-o
was replaced with far fa-comments
, which I believe is the same design.
I'm not sure why it's used over the solid variant though. Maybe it felt too bold?
We can definitely consider changing it.