Canvas is less of a piece of drawing software and more of brainstorm/mindmapping/idea workbench software. Excalidraw will satisfy different use case than Canvas and you can definitely use both!
I was using Excalidraw for (maybe unconventional?) mind-mapping, and one feature that I learned to appreciate is the ability to introduce unstructured objects into the diagram (e.g. add a box grouping arbitrary links, drop an image etc). I wonder how Canvas will hold up for such use cases.