Preparation for smart home - Which cable ducts are necessary?

Hello everyone, I do not intend to use a smart home system in my house. Nevertheless, I would like to possibly provide cable ducts so that it can be retrofitted later if needed. Therefore my question: How is a smart home roughly and generally wired? Is it all possible via WLAN?

Everyone.

Really now. There are 1001 YT videos about KNX and the like and even more discussions here.

It all depends on your chosen system and the desired scope. I believe in doing it right the first time or not at all.