bathroom layout option... what do you think?

I'm not a fan at all. Here some reasons:

Every time you took a shower it would spray into the tub and you'd have a huge area to have to clean on a more regular basis because of it.

Constructability of that layout is way more complicated than just a tub or shower or tub/shower combo. Waterproofing that whole area costs a lot more. Corners are the area you will get leaks and need to take extra precautions so adding a tub surround just introduced a lot of unnecessary corners. Tub surrounds are usually not waterproofed at all so you would need to be all over your contractor to ensure they are building it correctly or you will have a leak.

A shower and tub combo like this is called a "wet room" which means all of the walls above the tub as well need to be waterproofed = $$$

What your first picture and second Houzz link shower are actually curbless wet rooms which would mean lowering your floor to include a below the floor pre-slope so the finished slope matches the rest of the floor. That is a ton of work to do and requires that your entire bathroom floor be waterproofed along with a few inches up the wall (essentially your entire bathroom becomes the shower pan and curb). Also very expensive.