In a vacuum, having more features is good. But simplicity itself is a feature. Simple things don't break as often, it's easier to fix when they do, and they're more predictable, meaning it's easier to plan your life around them.
That said, when I set up Home Assistant, it was not without the need for some hobbyist motivation, but it wasn't too bad. That was over a year ago, and I have only gone into it since then to add a couple extra lights and set up a Christmas mode.
As far as the 'why', I can put the light switches where I want them, and have them do exactly what I want. I don't use voice or phone control, I have physical switches, but they're just exactly where it makes sense. An example is that in my living room I have a switch remote on the coffee table that lets me turn on or off all lights in view (kitchen, hallway, living room) and two different light scenes for reading or watching TV.
To me, it's actually simpler than flipping the 5 or 6 switches I would have to otherwise.