I doubt there’s been a house built here in the last 60 years that didn’t include at least one en-suite bathroom (usually called a master bathroom), associated with the biggest (again, master) bedroom.
In our house (which I’m tempted to say is a “bog standard” one

), the master bedroom has an attached bathroom, and the second bathroom is off the main hallway…directly across from one of the two guest rooms, meaning that while it’s not connected to the bedroom, it’s actually closer to it than the master bathroom is closer to bed in the master bedroom.
Usually, the master bathroom is also nicer than the one for everyone else, but in our house, both bathrooms are identical - just a tub-shower, toilet, and sink. Nothing special by any means.