Just a few ideas? Dark paint would be great! For another paint option over cement, you might try silver metallic and then blacken (yes even whiten) with chalk paint to see how you like it.

Simple tile in slate might be a perfect fit.

And of course, my favorite in utility areas: distressed or weathered pine. This can be achieved with plyboard to test-run the look. Wood will give stairs the safest grip possible outside rubber matting — and any matting looks great over the look. Apple barrel baskets on either side and you have country fresh feel! They might still be on sale at Hobby Lobby?

Love that you love EVERY INCH of your home!

Maybe not these specifically, but there are lots of other options for Stair Riser covers.

Cut a pine board to the width, and height of the wall under the threshold, and either stain it, or paint it. Looks like you have gray cabinetry. Is that going in that room? If so, paint the board the same gray as the cabinets. It will be very easy to touch up in the future, if you need to do so.

@cat_ky yes, the gray cabinets are throughout the garage.

https://commomy.com/collections/3d-peel-and-stick-wall-tile/products/3d-grey-whitewash-brick-peel-and-stick-wall-tile

Can easily replace when wear and tear takes a toll.

If space allows, install a new set of steps with three risers that meet code and a minimum 4' x 3' landing that is nearly the same level as the house floor.

I spoke with the contractor and he is redoing the steps. This will likely cover the majority of the blank space that is currently exposed. Thanks for all of the advice!