iPad could run iOS software since forever. Did it help iPad?

Compared to having even less software? Yes.

Compared to a hypothetical scenario where developers care to build iPad apps? No.

I don't think the availability of iPhone apps on iPad is what derailed development of iPad apps either, practically all the ROI building software for Apple hardware comes from impulse spending on the iPhone and even with 500+ million iPads in circulation today it doesn't come close.

	▲	troupo 2 hours ago \| parent [-]
		iPad was sabotaged by Apple themselves, as they never figured out how to position it, and what capabilities to give it. Multi-tasking? Half-assed. Keyboard and mouse support? Half-assed. OS capabilities beyond iOS on a laptop-like device? Non-existent. This was additionally hamstrung by "just check a checkbox, and a half-assed port of your app will run on iPad". We've now seen the same play out with MacOS: why bother creating an actual app when you can just run a mobile app? Even Apple's first-party apps do this now.