Front yard wall, slope/decline, what to do?

Hello everyone,
we are now in the process of finalizing the planning of our front garden.
The right side is not so easy, as you can see in the pictures, we have a slope from the front door to the right corner of the house. We would actually like to have a flower bed there, just like on the left side. Now the question is, how do you retain on the right? Would you build a concrete block wall? A railing would then have to go on top of the wall.

Everything is somehow not so optimal...
We are a bit puzzled at the moment.

One of the pictures is the suggestion from our excavator operator.
Best regards and thanks

I wouldn't have refilled at all. Stauden doesn't care whether it's flat or inclined

We are a bit puzzled right now.

I am too about modern art; it could use a little explanation here and there ...

I am also skeptical about modern art; it could use a bit of explanation here and there ...

Explanations in what sense? I can gladly send more pictures.

We also want, for example, that this ugly light well is no longer visible.
It should become harmonious and green, with bushes, trees, shrubs.
But then it is simply difficult—how to best manage that because of the slope.

I wouldn’t have filled it at all. Perennials don’t care whether it’s flat or sloped

But how would you cover the ugly light well?

What was planted correspondingly tall before. Maybe evergreen