It seems to me like where a period would be too strong and I want the clause after to be considered equally at the same time or possibly as a counterbalanced thing to whatever is to the left of it
If it were to parse it purely linguistically, it seems like not quite a list of things but perhaps a relevant after thought that a comma would be too weak for and a period too strong
You can also use it to separate items in a list when the items themselves contain commas, eg:
Attendees included Michael Simps, chair of the oversight committee; Allison Charles, VP of outreach; and Yasmin Blort, a local activist.