Windows: Brightness versus Thermal Insulation, Double Glazing / Triple Glazing

We are in the middle of planning our dream house and are currently wondering whether we should choose double- or triple-glazed windows. Basically, brightness is more important to us than thermal insulation. We saw triple-glazed windows in a show house and they did absorb quite a lot of light. Is there any reason against installing double-glazed windows in the living and dining areas and triple-glazed windows in the other rooms? We just don’t want condensation to form on the double glazing.

I have not noticed that triple-glazed windows block a lot of light. I assume that in this model house, other constructive characteristics caused the noticeable darkening.
Furthermore, you should not necessarily ask yourself: double or triple glazing, but rather consider the thermal insulation properties of the window. You can get both variants, for example, with a k-value of 1.1. The third pane would not improve the house’s thermal balance in this case (although it would for sound insulation).
Only if you want to build a house at passive house level, for example, would windows with a k-value of 0.7 only be achievable with triple glazing.
It is best to discuss this with your energy consultant so that the overall "house" package works well in terms of thermal performance.

Oh, so far I assumed that triple-glazed windows automatically provide better insulation than double-glazed ones. My energy consultant had simply recommended triple-glazed windows because they are "better"...

There are, as mentioned, better triple-glazed windows, but also double-glazed ones with the same k-value. This must be taken into account when ordering/planning.