Using touch for canvas is pretty cumbersome, and I think there’s limits to how much that can be improved UI wise. Adding mouse support, as in zooming in/out with scroll wheel, and using middle mouse button to move around would improve the usability a lot. This isn’t currently working at least on iPad, although mobile Obsidian seems to otherwise somewhat support mouse usage.
And drag cards，auto resize
Agreed. Really discourages use on iPad which is a primary use case for me.
I have found a way, system setting → Assistive Touch → simulate touch(I’m not sure about the english of this feature)