A wet room is just a bad idea. Think it through.

If you are concerned about aging in place I would reconsider a wet room. My mom is 86 and is concerned anytime she is near a wet floor. For such a large bathroom I would isolate the shower to the exterior tub wall, have the tub against the centre wall. It would make a nicer focal point from the bedroom door.
We built our home with pocket doors and love them. So much easier to clean around them. Much better when my dad visited with his walker.

Ah, aging in place. Well, as my dad said, you never know how your old age is going to treat you. My two parents had very different needs as they aged. Without even considering guests who might use the bathroom, too.

So, first, slab’s idea to isolate the shower, maklng a roll-in or low profile instead of a wet room, it a much better idea. That’s what was done for my grandmother and her caregiver, perfect.

That layout is a bad idea no matter how old you are.

Wet rooms are not all that easy to clean and , as others have noted, present the risk of slipping on wet tile.  Having a two-way powder room just seems like a bad idea in principle. If your house isn't large enough for a separate powder room for guests, then I'd have a single bathroom with a single door off the hall, just like the bathrooms in the houses a lot of us grew up in.

Hire a CAPS certified Kitchen and Bath Designer. Beyond technichal concerns over a wetroom, there are functional usability concerns with that design. It can stand a great deal of improvement. You might also have the designer put their eyes on the rest of the attached home, for a critique of accessibility.

Do you take a lot of baths? That would be the first thing to remove because as you get older, that is going to be used less and less. If you need it, I would switch the tub and the shower locations. Also , make sure the door ways are wider.

Also rethink the bench directly under the shower head.

Some comments about building a home for aging in place. You're not going to be able to think of everything or plan for everything. But I concur with all of the comments above, and entire wet room is scary for anyone but especially for someone with decreased mobility. All doors should be 36". Shower needs to be "roll-in," and ideally have a handheld shower head as well.

Also, shelves above the tub are very hard to reach, and hard to clean.

The doors will get wet and eventually fall apart. Interior doors are not manufactured for "wet" rooms.

One more thought- you want to plan for grab bars in the shower - and that layout doesn't really allow for them.

I think you can come up with a better layout for an "aging in place" bathroom.

I remodeled with a view to aging in place.

Do you need a bathtub? As others have pointed out most seniors do NOT take baths because it is difficult to use. If baths are an essential to you, then you should consider designing one that is as user friendly to someone who might have difficult rising and sitting in a tub. No kidding but in my limited circle I know two people who were trapped in their tubs - one for two days and one luckily had her cell phone and called for a rescue.

A built in bench is great. I have one but I have a handheld reachable by the bench and NOT a showerhead.

As others have pointed out, design with suitable grab bars in the shower and by the toilet and by the bath if you decide you need a tub

A curbless shower is nice but not really essential for most seniors as they can navigate a low curb - with the assistance of a grab bar at the entry or with the help of their home heath care attendant if it comes to that. In my experience with parents and senior neighbors none of them needed a wheel chair to get around their home or use the shower even if they did need one when they couldn't walk long distances because they didn't have the strength. But they got by fine in their home with a walker if they had balance issues.

A bathroom with motion sensor lights is a great safety feature as well since the light will turn on at night. You might also consider getting one of the "smart" lighting systems like Lutron Caseta so that you can control all the lights in your home from your iphone through voice command. No stumbling in the dark to find a switch as you can turn on any necessary lights from the comfort of your bed - and turn them off.

ETA You should also consider getting a Toto washlet or equivalent because many seniors have reduced shoulder mobiity or other issues in terms of "reaching" either after an operation or permanently so a good washlet really helps. My mother's friend also had some kind of issue with her fingers so had one installed. They are easy to install if you are remodeling because you can easily install the necessary electric plug even if you don't install the washlet immediately but it would be harder to install an electric socket afterwards.