@nathancu has added several good posts. I would just say that there is a place for some WiFi home automation devices in most homes, and it’s always good to have choices. 
First, anything that streams either audio or video is usually a very good candidate for WiFi, as it can handle the necessary bandwidth. That obviously includes video doorbells and audio assistants like Echo and Google Home. But there have also been a couple of WiFi smart bulbs that had music streaming built in, and that’s a good use case for WiFi.
Second, WiFi has much longer range than either zigbee or zwave. If you needed to automate a light in a shed and it was too far for zwave, I could definitely see a WiFi bulb being a “Simple solution” candidate there.
Then there are a few individual manufacturers like LIFX who offer features or form factors that other bulbs don’t typically have. For example, they have a popular mini bulb which may fit some small table lamps other bulbs won’t. And an LED strip where you can control different sections of the strip independently. Neither of those required WiFi, but WiFi is what they chose to use, and those specific devices are popular for those features.
But those are edge cases. Most of the time he’s absolutely right: if you already have a hub, WiFi isn’t usually the first choice for a light bulb protocol.