What actual benefit is there over a PHD over a masters degree in physics?

Can somebody please tell me the answer?

If you have a PHD, you could be a professor.

I don't want to be a professor.

You can make people call you doctor

Why would I spent three years getting a phd solely to be called a doctor

Because you want people to call you doctor

You made that assumption that I would want to be called a doctor despite saying I don't want to be a doctor.

Then dont become a doctor. For real tho: More and more people are taking masters, so with a PHD you might be more likely to get a job.

You can become a professor with a Masters too. None of my proffessors are Doctors.

People without an MD, outside of an academic institution asking you to refer to them as "doctor" are morons. The only application a philosophy doctorate has is on a campus; hate to break it to you non-MDs, you're not "Dr." anybody.