Draw - from a quick sketch to a complex plan, Draw gives you the tools to communicate with graphics and diagrams. With a maximum page size of 300cm by 300cm, Draw is powerful tool for technical or general posters, etc.
Libre office draw is wonderful, it can edit pdf docs at ease. It’s crazly powerful compared to paint 3d
Scribus - Scribus is a desktop publishing (DTP) application.
draw.io - Online diagramming application
Affinity Publisher - Professional desktop publishing app
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Xpublisher - Xpublisher is a content publishing software that helps you to structure your content and then allows you to easily publish the content on various platforms.
Dia - Dia is a GTK+ based diagram creation program for GNU/Linux, MacOS X, Unix, and Windows, and is released under the GPL license.