I was a little surprised, but pleased, to see that Lidl are launching a smart home line this week, which is all ZigBee too - that is definitely not niche either. They even mention the interoperability and privacy as selling points!
The bigger hassle seems to be different zigbee hubs that have varying levels of compatibility, so while you can pair the devices you can't get the data you want.
I've just been down the research rabbit hole, and about to try using zigbee2mqtt to bypass this nonsense (this also then means the only internet connectivity will be through a device you control)
Philips Hue hub talks to diagnostics.meethue.com all the time, and it gets kind of annoying already in the pihole stats.