What would you do differently in the next house construction?

Sorry for the stupid question.

What exactly is this lighting planning and why is it necessary?
(Oh, by the way, I'm not an IT tech freak, I only need 1-2 spots in the shower and I don’t want anything automatic. Just classic old-fashioned without any gimmicks

You can do a lot with lighting (regarding room feeling, coziness, good working light for kitchen, office, etc.) and also ruin a lot if it’s not well planned (a classic example is the spots in the ceiling in the kitchen as the only lighting, and when you stand at the work surface, you cast shadows on yourself).
Also especially in areas with dense buildings, a properly planned outdoor lighting can help against being looked at from outside without always having to keep the blinds down (which I find claustrophobic).
Often also the living room lighting: there is a lamp planned in the middle and I really don’t know ANYONE who lights their living room in the evening with the ceiling lamp. Instead, people have indirect lighting in the form of various lamps around. You can plan that right from the start.

We will definitely hire a lighting planner and compared to the total construction costs, this money is not negligible but it’s not that much either (about 3500€).

For the fact that I then have good lighting for all situations and we get a complete wiring diagram for the house. Communication technology, building services including.

- really cable every room with LAN (even kitchen, bathroom, and storage room)

Since we are currently planning this, the question is what arguments support it? So even planning something like this in the storage room...?

You can, for example, wonderfully hide an access point there.

Often also the onion lighting: there is a lamp planned in the middle and I really don't know ANYONE

then you know one now

Since we are currently planning this or are asking the question, what are the arguments in favor?
So planning something like this even in the storage room...?

Storage room might be an exaggeration but you are simply freer in the technology, no WLAN modules needed, interference-free transmission rates, for whatever reason.

In our case, the network was laid with the antenna sockets, I think that doesn't create much extra effort.

Since we are already on the topic of lighting design. Does anyone know the "Paulmann Corner Profile" for indirect lighting, the ones that you stick to the ceiling? Is there a cheaper alternative to them?

Since we are currently planning this, what are the arguments in favor? So planning something like this even in the storage room...?

It might be a bit exaggerated and I am probably not the "normal user" of electronics, since I really enjoy playing with it and like to connect as much as possible. For example, I use many TV clients (tablets, PCs, etc.) so that I can watch TV in the bathtub or on the terrace. Sometimes, however, the Wi-Fi throughput is borderline with HD programs. In addition, almost all electronic devices today have internet access. It starts with robotic lawn mowers and vacuum robots and does not stop before dishwasher, oven, and refrigerator. Whether you will ever need that at the freezer in the storage room, I do not know yet, but during my life (parents' house, many rental apartments + own home) I have repeatedly been annoyed by a missing power outlet or a missing network socket. Since you can also quite well install and wire LAN sockets yourself, I would be more uncompromising today: at least one double socket in every room.

In an emergency, as already mentioned, you can connect the Wi-Fi APs there anyway, which you still need for mobile devices. Wi-Fi is a great thing, but beyond a certain number of devices, throughput simply becomes very tight and proper prioritization of data flow with multiple APs is also very difficult. Moreover, wired connections are significantly more reliable. My heating system in the basement sometimes takes a Wi-Fi break. Not great if you have possibly linked alarms to it. Unfortunately, it was not available with a LAN connection.