Ask a marketer where the work lives and you'll get four answers.
The annual plan is a deck from January that stopped being true in March. The personas are older than that and nobody opens them. The brief is a doc with comments from spring. The calendar is a spreadsheet with three tabs and a colour key nobody remembers agreeing to.
That isn't really a tooling failure. It's what happens when the thinking and the doing get done in different places. Every handoff drops the reasoning behind it, and by week three you're relitigating decisions you already made.
Mindomo holds the whole span: the strategy, the reference material your team keeps returning to, the briefs, and the dated plans you run from. One file, four views, nothing re-keyed.