" My contractor tells me redoing the shower is my largest expense "

It will be for sure. Redoing the shower will result in an almost complete demo since the walls and the floor all tie in with that tile. Although the new tub will not be inexpensive either. Do you really use the tub? What are you looking for in the way of help?

Thumbs down to the giant soaking tubs of the 1990’s. You have a large bathroom that is not very useable. Save $$$ and start collecting photos in your Idea book before jumping in. A bathtub if used is a great feature also if you plan to sell in 15 - 20 years. So happy we have tub/shower in gust bath but shower only in primary.

Take baths daily, so a tub is a must

Start with budget and goal. What can you afford to do? Yes, the shower is a completed gut demo. Though I'd suspect a new tub will be too.

If you merely are trying to make this space feel less busy you can accomplish as a stage one revamp on more of a shoestring first and see if it takes care of your desire for a more streamlined look. If not then move on to more expensive options.

Stage one revamp: Paint the walls, all trim, including window and mirrors, a lighter color that is more seamless with the color of your tile. Swap all of your black hardware and faucets for chrome in a more streamlined shape. Paint your vanity. Declutter everywhere.

If you like the result you will have save a lot of time and money.