My opinion will be biased because I have very similar tile in my master we redid 12 years ago. 4" squares on the diagonal for the shower floor and 12" squares on main floor and up the shower walls. Coincidentally we are in process of redoing my kids' bath the past few weeks (it was also redone 12 years ago) because a hard-to-find leak in the tub prompted us to consider replacing it....which then brought about the issue of replacing the tiled tub-surround that would be damaged...and we would also have to try to retile some spots on the floor because a new tub would be a smaller footprint leaving some bare spots once old tub was pulled out. My point is that we also had to figure out the whole, "do we do an updated 'patch job' to save a lot of money, or do we just gut it and accept the cost as the price of being at peace with it/enjoying a new look and improved function. Right or wrong...which is always a very subjective thing....we gutted it and I'm thrilled. I was not interested in painting my cabinets just to have them have peel-issues due to steam, and we also got rid of the tub altogether and opted for a stand-up/walk-in shower for my older kids. Resale was considered on this issue...but by the time we move, someone can either love it as we've made it, or we will price the house with an "allowance" in mind. The old space had hot-chocolate colored walls and 'slate' porcelain floor and tub surround...an overall warm and cozy feel but also tired and dated. The new space is a porcelain 'marble' hex with white subway walk-in shower that is awaiting glass doors...an overall calming feeling that is also bright and fresh. I now actually wish SO BADLY that I was able to redo/retile MY whole bathroom (tile similar to yours). And there's nothing wrong with my bathroom, and a planned paint job on the walls will help me like it even more...... In my kids' bathroom, however, even unfinished with the floor and shower tile installed just waiting for the rest to come together (waiting on backordered tile base moulding) ......... I walk in and just smile and breathe deeply because of the way the space now makes me feel :) So my very biased vote is to gut it ;) ;)

What about a pattern for the floor? And you could do a larger format subway in the shower walls? I’m doing this on the floor of my small bath https://www.lowes.com/pd/Satori-Nouveau-Circ-7-in-x-7-in-Matte-Porcelain-Encaustic-Floor-and-Wall-Tile/1001220890

Since you seem to love this tile, what about trying to use a white caulk in the corners instead of the contrasting color. It may make the tiles look like they fold into the corner. You can try this before by just cutting some strips of paper and taping them up , then step back and see what you think. On a side note - was the floor tested for water? Those tiles are too big for a regular shower drain - it probably should have been a trench drain, unless there are diagonal cuts through the tile pitching them all to the drain ( can't tell in the picture ). Be careful moving forward - there seems to be some incorrect things happening here. Good luck!

@la_la Girl Thanks for responding. Many of the choices are either busy via matching floor and wall tile or smaller tile like 8-9 inch hexagon on the wall or floor (I'm personally not a hex fan). We're considering a lighter version of the current floor tile (the one on the left in this picture). But then I don't know if that'd make the bathroom a little too boring with the shower tile and if the undertone still works as well?