Get familiar a bit with ioBroker or openHab or HomeAssistant.
That is the third step before the first. All the tools you mentioned are software solutions for the management of the already existing infrastructure. But this must first be created.
But I don't even want to know what the 45 bus cables to my sockets alone would have cost...
In the basic equipment everyone always wants anyway, exactly 0 euros.
and where I should accommodate them in the utility room... I probably don't have the space for such a cabinet, with 6.5 m² utility room.
There is always enough space for bus cables in the control cabinet. They hardly stand out. In the basic equipment, there are 1-2 pieces for the entire building and the outdoor area.
About the radio failures... you're not in industrial production, are you? If the TV suddenly goes off or a light switches on/off unexpectedly, which was not desired... one can live with that. We're not talking about a paper machine or glassworks where you can throw away the daily production if the system suddenly fails.
Well, I would find that annoying. Or rather, consumer automation systems have their bad reputation because they are crookedly programmed or set up and then do not work anytime as the user desires. And let's be honest, why should one put up with half-baked solutions (especially in one’s own new building). For example, I cannot live with that.
KNX relies on presence detectors which then switch everything
No, you have a completely wrong idea. Light control is only one part of the whole. KNX thrives on connecting systems that would otherwise be incompatible and would work alongside or past each other.
Can KNX even be implemented sensibly if you have a big dog 40-50 kg and he is allowed everywhere in the house. The dog would trigger the presence detectors every time, wouldn’t he?
I find that super practical. We have two cats and although they are much smaller, I have deliberately dispensed with small animal suppression so that they can trigger the presence detectors.
What concerns do you have about the light? Let it trigger. It’s not a conventional switch on the wall that you have to operate. It also turns off by itself. For the different scenarios (e.g. night or sleeping) there are then also 100 solutions so that it is not triggered after all.
Now you already use KNX synonymously with automated control. As I said, it can also be different. Do something else for a day, it’s already turning into a psychosis with you.
Precisely. Reducing KNX only to light and automatisms is a bit harsh.