This is how I imagine the very first LIFX design meeting going:
Engineer #1: Hey, we should allow customers to Group lights together, so that if they have an exercise room in the basement, and a laundry room in the basement, they could make those two separate Groups. That way, if they wanted to turn on the lights in the exercise room, all they’d have to do is run back upstairs, hunt for their smartphone, log in, find the LIFX app, launch it, scroll down to Groups (assuming it’s visible; otherwise, they’ll have to click Groups before it shows up in the app), then keep scrolling down until they find the Group they want to turn on—in this case Exercise Room—and then press the on-screen button to activate it. Then shut off the phone (placing it somewhere safe), run back downstairs, and then go back upstairs because they totally forgot why they went down there in the first place.
Engineer #2: Hey, that’s a great idea! What about having Groups of Groups so that they could turn off the exercise room, laundry room, and any other room in the basement by creating a parent group called Basement?
Engineer #1: Nah! Who’d ever want to do a stupid thing like that!
Don’t ask whether LIFX engineers (who I’m sure are all smart, beautiful, talented people) completely dropped the extensibility ball, but ask this question instead: why in God’s name would anyone EVER control their lights with the LIFX app in the first place?! As mentioned in previous comments, the whole point is simplicity through automation, and I can’t think of an easier way to control the LIFX lights (which I love, btw) than by simply speaking a command.
And it sounds something like this: Alexa, turn on the exercise room. Alexa, turn the laundry room brightness to 100%. Alexa, turn off the basement.
That’s right, the answer is not shoving a square peg in a round hole, but rather bucking up for a few Amazon Echos. Last Christmastime 2018 they were $25 for the dot. If I asked you, “I’ll implement Groups/Subgroups in the LIFX app, but it’ll cost you $100,” would you do it? I would, and that’s why I bought 4 Echo Dots.
Alexa does not actually use the Parent/Child paradigm, meaning that you can’t make Groups of Groups, but it’s a piece of cake to make any number lights go into any number of Groups. Problem solved.