I still fail to see the advantage of routing your lights through an iOT setup as additional failure points, so you can use some unergonomic touch panel or unreliable voice assistant where a simple switch on the wall would have sufficed.
As someone who has professional installed and programmed automated lighting systems, allow me to share.
At the professional level, lighting is considered a life-safety function and typically requires municipal inspection to ensure stability (for new construction). These systems are indeed more fragile due to multiple points of failure but they're well established brands and are incredibly flexible and robust. This is why the "real" stuff costs a lot more than something like a Philips Hue light bulb.
As with most things in life, people are willing to pay for convenience (ex., Spotify, DoorDash, Prime). Sometimes even when that convenience is less convenient; in other words, novel. For multi story homes, the ability to turn all the lights off when you leave the home is a convenience. Setting a lighting scene in multiple rooms with the touch of a button, or instructions to Siri, is a convenience. Setting lights to 2% dimming when you wake up by speaking, "Good morning Siri" is a convenience. Holding a touch screen in your hands to monitor and adjust the brightness (and/or color) of every light in your home is a convenience. If you have a schedule that repeats every day, you could program some lights to dim to certain levels throughout the day - like when you leave and come home from work. This automated schedule could work in conjunction with an astronomical clock so lights turn on earlier in the winter and later in the summer.
Having worked in home a/v and automation for twenty five years, I can tell you that automated scene setting lighting is by far the most impactful thing I have ever worked with. It's like magic and it actually has an impact on your mood and well being.
Moreover, for most consumer grade lighting control, you're not losing manual control. If the interface loses connection or you're unable to access a "smart" device, your light switches still work as normal. If you're using smart light bulbs though, putting the light switch in the off position creates an air gap and prevents you from operating it elsewhere. A smart light switch typically avoids this issue and offers both direct physical and intelligent control.
I wholly agree with "unreliable voice assistant" but there's much more to it than that. We were using voice assistants in the 90s that were nearly as good / bad as Siri. Although, you had to pre-record each voice command back then. If nothing else, it was novel.
I also agree with "unergonomic touch panel". That would be ridiculous to have to unlock your phone and open the Home app to turn each light on / off. For general use, I prefer physical buttons. Some off the shelf products today support buttons, like Ikea. I also use Apple's Shortcuts and Widgets to more easily access scenes that I've programmed from any device and any location in the world. Apple's Home app is absolutely trash when it comes to user experience so I find this is the best way to operate lighting.
If you adjust your perspective from turning one light on from 0% to 100% towards setting dimming levels and programming lighting scenes that can be controlled without having to walk to the corner of the room, I think you might better appreciate "the advantage of routing your lights through an iOT setup".