Microsoft Visio has been around for years, but with the rapid adoption of tools like Confluence , new players showed up to disrupt the market.
Within them, Draw.io(now Diagrams.net) and Gliffy are excellent alternatives to draw diagrams quickly that can easily convey concepts and ideas.
Going beyond them, written diagramming such as PlantUML (and tools like www.planttext.com ) can accelerate the speed of writing documentation. As instead of spending minutes to move arrows from A to B, you can simply write “A->B:Message” and the diagram will be rendered
Whilst MS Visio still has unique features, many professionals might choose simpler options that integrate with tools like Confluence
What do you use?