They serve vastly different purposes. Lemmy would be a terrible place for people to chat about how their days are going, which is a key part of what microblogging platforms provide to be honest. And conversely, for structured conversations focused on specific topics, Lemmy has obvious advantages.
Beyond the basic structure, there are cultural issues with both that make them a bit tenuous for me.
The question is, if there are instances that are full of transphobic content, and they’re reported, does firefish defederate them. If they do, the view will improve. Although, global feeds are never very useful.