[ajsnigrutin]

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 "waste" them, makes you build a tool around what you have, instead of using just what you really need.

[vidarh]

Yes, you can, but I have no interest in building my own. I don't need these things badly enough to be willing to invest much time in it.

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.