We've been using Trello for a while and I've never thought of it as bare bones. It seems quintessentially kanban, in your opinion what's missing or simplified?

We've been using Trello for a while and I've never thought of it as bare bones. It seems quintessentially kanban, in your opinion what's missing or simplified? Do you have any opinions on "calendar kanban's" like Sunsama: https://medium.com/@landon_46280/scrum-with-sunsama-ddb5e8e76876 https://medium.com/@landon_46280/scrum-with-sunsama-ddb5e8e7...