Main lighting with LED strips: is it useful?

Because of the costs, it is a bit difficult. The ceiling without coves and lighting was included in the project. The electrician still has to say something about how he wants to do the light control. Dimming is still to be added along with the cable routing to the distribution box. I only want to afford all this because the ceiling without lighting was already included in the project. Otherwise, it would be way too expensive. For the lighting installation as described above with power supplies, costs of approximately €20,000 will be incurred. I will meet the electrician about this matter in 2 weeks.

Of course, there is always the cheapest Chinese goods, but complaints are inevitable. That is why my kitchen fitter no longer installs LED strips in the kitchen. Only a few people are willing to pay the necessary money for high-quality goods.

whether the performance of LED strips is sufficient to do without classic ceiling lamps, which I actually intend to do.

I believe the issue is rather that a person needs the light source "with them," and not on the wall.
When I work, search, or live: I prefer the artificial light source to be at or behind me rather than in front. It also has to be able to brighten the shadows of daylight. This happens more in the center than on the walls.

Off Topic:

Mixed in the living room with the dining area.

Your lens or the applied editing distorts your room quite unrealistically ;)

It still needs to be clarified which KNX system (Busch-Jäger or Jung) or which lighting control should be used.

Is that nonsense really still prevailing? Other manufacturers have significantly better dimmers or LED controllers. However, the DALI-KNX gateway from Jung is good (it's OEM anyway).

Especially regarding lighting control: via DALI or DALI + KNX or DMX or 1-10 V control?

You can cross DMX and 0-10 V off the list. That makes no sense here, plus DMX in a private house is really no fun. Whether DALI or KNX (if you also have KNX, autonomous DALI is not an option) is purely a matter of calculation. DALI makes financial sense with purely white dimming circuits from about 25-30 dimming circuits, with RGB(W) much earlier. Practically, it already makes sense regardless of the number of lighting circuits if, due to power feed, you would have several lighting circuits that should function together as a single one (long coves in large rooms, for example). Such groupings work better with DALI than with KNX.

Dali would only be an option for me if I were to do without KNX. The situation with the lighting circuits in our apartment is manageable. I don't have much knowledge in this regard and have to rely on recommendations, but I also believe that the combination of DALI and KNX could be more expensive than just pure KNX and doesn't offer many advantages.

I believe the issue is more that a person needs the light source "with them," not on the wall.
When I work, search, or live: I prefer the artificial light source to be at or behind me rather than in front. It also needs to be able to brighten the shadows of daylight. This tends to happen more in the middle than on the walls.

Off Topic:

Your lens or the applied editing distorts your room quite unrealistically ;)

What do you mean by the room being distorted unrealistically?