http://www.theendofownership.com/blog/2016/7/14/ftcs-revolv-...
To clarify, the $300 wasn't a lifetime subscription fee, that was the whole price of the device which was sold with "lifetime subscription" as a major selling point compared to competitors with monthly fees.
Another similar story, Wink hubs were sold as not needing a subscription, and then added one later. Announced with 1 week warning, date was pushed back, but went into effect earlier this year. If you don't subscribe, it mostly stops working.
I can't imagine buying a non-subscription smarthome device unless they can be managed locally with Home Assistant or similar.
At least when you buy a device advertised with a subscription you know they have a business model. Except for certain companies where that business model is "We love to discontinue all of our projects."