I'm having trouble imaging how planks across a tub could look nice.

If you are not concerned that others will view the space, you could uses the whole tub for storage and hang a pretty shower curtain on a tension rood to hide the space.

There appears to be a view through into the area from the bedroom. Close the panels/slats. Take measurement to see if you have enough room for a decent tub and the bedroom closet, particularly if you want to hang clothes. I'm not a pro, but I think you need to know if you can use the drain in its current location or not.

Curtains are a great suggestion.

Instead of curtains I was considering installing sliding Shoji doors running along the edge of the bathtub which, with the two overhead lights above the bathtub already, might give off a soft white light through the translucent screens without revealing the storage behind. However, I wonder if there’s a better option than either a shower curtain or Shoji doors? Thank you both for your suggestions!

I think the solution will partially depend on how long you intend to use it. If you plan to do the remodel soon, I would not invest the time or money in the sliding screens. If the remodel is years away, or possibly never because you decide to move away, then the screens might make you more comfortable with a streamline look.

My mother used her tub for storage - hang an extension rod and some curtains if you want to block the view.

You can put down some kind of grid on the floor to raise the level of the floor and then use the surface of the tub bottom for surface

I used the shower stall in my guest bath for storage - seems to be in my DNA. I essentially used it for storing Costco amounts of toilet paper and whatever other stuff people use pantries, basements or garages for. I wasn't particularly concerned about the aesthetics since the shower itself had hideous frost acrylic :-)

My DS put a pretty fabric shower curtain. They store their suitcases in the tub. It looks fine until they remodel.

It looks like a tub for two. :-)

The last two comments are spot on. The oversized tub is dead space to us, and our apartment is in Manhattan where every single square foot counts. A poor design decision by the architects. Not to mention the louvered “exhibitionist” doors that open into the bedroom with its 8’2” windows haha! The architect who designed this new development is famous but this decision was ridiculous.

In the interim, I think a tasteful shower curtain would look fine and be the most cost-effective option until we’re ready to proceed with removing or downsizing the tub. I also like the idea of putting shelves on the bathroom side of the louvered doors, something I hadn’t thought of before and will look into. Thank you for all of these comments, very helpful.