depending on the style of the rest of that floor,I would consider painting the doors to match the rest of the walls on that floor...another option might be to mimic that framing in a wainscotting effect and use it on the adjacent wall using baseboard trim or picture frame moldng& paint it out the same colour as the doors[in a stin not gloss finish]...[I would also paint the wood framing on the slanted wall above it out a neutral colour...or the same colour as the rest of the wall...as it sort of draws an arrow to the area...]

paint out the same color as the walls so it recedes

Paint it out. Tuck in a cozy chair and light for reading, or baskets for storage...

Paint it. Then pop some balloons under there. Like, literally pop them not like a pop of colour put them there.

I also agree to paint it so it matches the wall. Does it have close proximity to the garage entrance? It might make a good "drop zone" for keys, coats, shoes, etc. Hang hooks on the long, angled wall and tuck a bench with a shoe cubby against those doors. Odds are you aren't going to be getting into that crawl space very often.

I have the same idea as Mon, turn it into a closet.

I was going to suggest bookcases but Mon's idea is genius.

A closet would be a bigger project, but you probably don't access the crawl space more than once a year, and the closet would be very practical. I think your stairs would feel better with a wall on the left side. While your at it, remove that carpet and refinish them to match the other wood for a fresh new look.

Paint then in white wash, hang a nice colorful picture on wall, remove carpet from stairs make them in wood combine with some Mexican style title on back of step

Embrace the creepy, and put a picture of the twins from "The Shining" on the doors. :-)

Or remove the doors, put shelves in and turn it into shoe storage.

DO you have pets? It could be a cozy nook for a pet bed.

Ideas

If you don't feel like adding a closet, get a dresser or chest to place in front of it, with a small lamp on a timer to light the area. If you get one with wheels or casters, it would be easy to roll it out of the way when you need access.