Earlier quoted context omitted.
The alternatives may be cheaper if you can find one that does what you want . But in terms of the ability to quickly throw something together where existing stuff doesn't quite do what you want or is locked down, it looks amazing. In terms of "serious use" I think that depends on what you mean by "serious". E.g. my hone automation setup is not static, because I keep finding new little things I want to tweak, and ofte…
You can always get the same components that this kit uses, solder them together and do it cheaper. Want a dimmer for your smart lights? esp8266 + one of many potentiometers available + maybe an adc if you need more than one. You'll never use this whole kit just for one potentiometer, with the rest of the components in a drawer somewhere, because this would make it too expensive. Cramming multiple modules just not to…
Things like a single dimmer etc. is not the problem, because for simple stuff like that there are plenty of off the shelf options.
The issue is anything that deviates from what manufacturers expect. And yes, I'd be happy to use a lot like that for that even at a quite high cost because the existing options to do it cleanly without a self build are also expensive.