I can't really even find z-wave bulbs right now. And basically any device I might want (curtains, alarms, sensors, lights, motors, thermostats, etc) comes in a zigbee form.
I agree that Z-Wave did the better standards enforcement, but Zigbee went with the age old route to success: manage to be cheaper.
Throw in that the two most common automation situations tend to be either:
1. Upstream cloud service
2. Local management engine (ex: HomeAssistant, OpenHab, etc)
And it just doesn't really matter all that much how compatible devices are in terms of point to point control. I can just route the message through HA and take the action I want - mixing and matching as needed.
Plus - Alexa pro ships a directly integrated zigbee hub now, which got a lot of devices moving that direction, and Ikea makes some great super cheap zigbee devices.
Bluetooth and Wifi devices are the worst of both worlds, in my opinion. Wifi usually needs integration with an upstream service which is a non-starter for me, and bluetooth is just really limited on total device count. Both also eat through a lot of power compared to z-wave/zigbee.
It's pretty cool that several recent zigbee switches are completely battery/wire free. They literally use the energy you expend to push to the button to send the signal.