Opinion needed: Best text editor features for getting stuff done

Hey all, revising the text editor in Dendri and since most of my users are non-technical I figured I'd ask some devs/creators so I can get a broader sense. We have text editors inside our cards (like a Jira ticket or trello card) and on our dashboards as free-form notes areas for teams and individual users. What features would be most useful for you - who does this best in your opinion?

I'm thinking things like copying/pasting images/screenshots, markdown support, etc... we have discrete commenting, so I'm not sure mentions would be that useful... specific embeds? Just curious. Want to keep it simple but make the changes throughout our app so there's a consistent and enjoyable space to work with longer form text.