I only wear sports leggings occasionally for exercise, so I can't really represent the view of women wearing leggings as pants in everyday life, but I guess the main reason is that they're very comfortable (unless they're shapewear). I would compare their comfort level to sweatpants.
One idea is to browse the hashtag #introduction and follow people whose introductions sound promising to you. The hashtag #FediTips might also be useful. If you want to follow scholars and scientists, there is this list grouped by discipline: https://github.com/nathanlesage/academics-on-mastodon
And in general, you can follow hashtags on Mastodon, e.g. "#bloomscrolling" for pictures of plants.
I only wear sports leggings occasionally for exercise, so I can't really represent the view of women wearing leggings as pants in everyday life, but I guess the main reason is that they're very comfortable (unless they're shapewear). I would compare their comfort level to sweatpants.