"why wouldn't companies just use WP instead of CORONA...? Given...

"why wouldn't companies just use WP instead of CORONA...? Given that their overall function is the same. Minus a few added perks to CORONA?"

The advantage of CORONA is that it integrates with a company's internal phone system and turns your mobile into a mirror of your extension on that system. So if I'm going overseas and I redirect incoming calls to my mobile to my company desk phone's direct line, then all calls made to either my mobile number or my desk phone will reach me on my mobile anywhere in the world at very low cost.

But you are right, companies who are on the fence about the system can trial it using Worldphone and get most of the benefits without making any changes to their internal systems. I've said it before, I think the success of worldphone could mean a slower adoption of CORONA, but it doesn't matter, Norwood will still get the business one way or another.