The value of Hugo is that your meeting notes are linked to your meetings and the people and companies that attend them.
By linking meeting notes to meetings from your calendar, Hugo makes it easy to find information when you need it and can also remind you to write notes when a meeting is about to begin. Hugo also allows you to share meeting agendas in the calendar description of your calendar events, so everyone is prepared and on the same page.
To support this functionality, Hugo requires access to your calendar data using the Google or Microsoft O365 APIs. Unfortunately the permissions they give us are sometimes described in broader terms than how they are actually used by Hugo (you may notice a right to delete calendars for example, which is something Hugo does not support).
Hugo will never remove, edit or write anything else to your calendar.