I used Notion for managing my D&D campaign until I noticed I was approaching the limitations of what the free tier offered. That sent me looking for an alternative and I ended up settling on Skiff Pages (at that time I don't even think they had email, drive, etc). It didn't have all the features that Notion did, but it was functional, easy to use, and they were frequently adding improvements.
It's kind of funny to me that they ended up getting swallowed by Notion in the end. I'm just glad that I've long since switched over to Obsidian. My Markdown files can't get bought by Notion . 😂