Leftists know a thing or two about infighting. If X becomes the right wing space and bluesky the left wing one, they can soon point at each other for "look, the other side doesn't even get along" gotchas.
Bluesky seems a bit more like a 140 Characters mashed with Reddit with subtopics/submods of feeds as the focus. Also it seems to highlight the custom feeds feature which you can manage yourself. Twitter/X has such features but for the most part you are nudged away from these to improve "engagement" metrics. That said its highly possible that could change over time based on the long term vision.