I don't (and won't) use Google Calendar, so there's still a cost to me. In fairness, I don't use Notion either, and wouldn't start for a calendar (I've tried,

I don't (and won't) use Google Calendar, so there's still a cost to me. In fairness, I don't use Notion either, and wouldn't start for a calendar (I've tried, but I seem to be one of the odd people for whom Notion is radically, deeply unintuitive), so this particular switch wasn't on the table for me in the first place.