i don't think it looks bad. you could:

window film

a few shelves that span the glass, and put on some trailing ivy plants

use some type of window shade

cut a piece of dry wall, finish and trim it out, paint to match wall,,then hang a picture on it.

some kind of tapestry art or piece of art to fit inside.

Really,,,it's not that bad. put a taller plant in the corner or hang one from the ceiling above it and let the vines trail down. like a large Pothos ivy plant.

I agree with Beth H that it doesn't look bad. But I've never minded glass block.

foam core with a nice large repeat fabric mounted over it? try upholstery fabric, in remnants at a good fabric store.

Tapestry art would be a nice, easy solution. You'll lose the light you get in the shower, though.

I don't think it looks bad either. But, if it really bothers you, you could mount sheer or patterned curtains on rods at the top and bottom.

It doesn't look bad and I'd leave it uncovered because it provides much needed light for the shower.

That said, if you hate it, cover it by hanging something over it. Make sure it is something suitable for a bathroom.

Measure the space you need to cover, have a piece of "finish" (smooth) treated plywood cut and sanded and painted your favorite color (or even wallpapered) and then framed ... put it in a thin wood frame ... as if it were a picture: Instant accent wall.

Note: Know the size of the frame you're going to add as you measure and pay attention to the space that will be left uncovered -- center whatever solid item you hang on that wall.

Note: If you choose to hang a plant, heart leafed philodendron would grow well there.

If you’re remodeling in a few years I’d just leave it. Who sees it other than yourself (s)?

You could put a roman blind on the tub side...

Is there a light in the shower?

Maybe a glass bead curtain? I agree that pretty much anything you do with make it look worse, and you will lose light. Personally, I like the way it looks.

You could have a piece of frosted glass or even drywall installed over it so you wouldn't see it anymore.

Peel and stick wall tile? Can't really see what your tile looks like, but maybe something to coordinate/complement it? You could install something linear with it running vertically, like a waterfall.

https://www.wayfair.com/home-improvement/sb0/peel-and-stick-backsplash-tile-c1864259.html