This is a similar argument with other HN discussions "why go AWS when you can just host yourself". Yeah, everything is doable and nothing is difficult to learn, but just a bit of this and a bit of that and connect all together and suddenly you face hours and hours of smart home maintenance you wouldn't need at all otherwise. Because every bit of smart maintenance comes on top of dumb maintenance. Of course if DIY is your hobby then it doesn't count as work, but I have other hobbies so a smart home is not a priority for me - until it either works plug-and-play or becomes so standardized (and cheap) that I can call a technician to do it for me.