Wayland is not related to the X Window System, it is a ground up redesign.

And while Microgui is nice it purposely isn’t directly comparable to a compositing window manager.

What is QNX's business model nowadays?

I understand Ford Sync3 is based on it, but are there other consumer-visible products based on it?

Until recently, Cisco's IOS-XR was based on the QNX microkernel.

https://en.wikipedia.org/wiki/Cisco_IOS_XR

195 million vehicles, and "We are the embedded OS of choice for ventilators, train controls, factory automation systems, medical robots and more."

Many other car brands (often just the instrument cluster though). Otherwise probably not much consumer stuff, way more industrial/medical/infrastructure fields.

The navigation/entertainment unit on our Suzuki uses it (I pulled apart the firmware update out of curiosity)

BMW’s iDrive (used in all their production cars since around 2011) uses it