Kind of like asking if you take your keys with you when you leave your car. I just do it out of habit. I'm sure if you posted the same question about keys, there would replies about how leaving the keys in the car was really logical. I worked with a guy who wouldn't consider a Prius because it didn't have the "feature" of being able to lock the keys in the car. I set the brake in the garage and I almost always try to take the keys in to the house with me.
The person that you worked with is misinformed. You can most assuredly lock the "keys" in a Prius. In fact.....there is a fob locked in mine as I type this, with the keylet secured in an undisclosed exterior location. I did take the battery out of the fob, but I'm able to get into and drive my car away if something happens to the "keys" I normally use. Nobody plans to fail, but sometimes they fail to plan.
I always set the parking brake and leave it in gear in a manual. In an automatic, I usually only do it on hills (especially with foot parking brakes, yuck). I'll sometimes do it on flat ground in the Prius if I'm going to be loading or unloading it, to prevent the slight roll in P.
I remember reading auto stuff where the parking brake seemed to use the same braking mechanism as the regular brake hydraulics. That got me wondering if that is always the case or only on certain cars (implying others have a parking brake that is physically a separate mechanism from regular brakes). This feels slightly more physically secure to me than simply leaving it in the parking gear, which I imagine to somehow put unnecessary "pressure" of some kind on the engine or transmission itself especially on a hill. Since I'm not actually sure how all these work though, I wonder if someone here does and can explain.
Some cars, such as my old Subaru, had a small drum for the parking brake, separate from the main rear disc.
What is a parking brake? Wow. I've been driving for 45 years - manual and automatic - and never use the parking brake. I don't know what people are referring to when they talk of lurching. My cars never lurch. Oh well.
Always on every car, auto or stick. We have both and we always set the brake. Saves wear on the transmissions and takes pressure off the dogs that keep it park.
Lurching, is when you release your foot off the brake pedal, the car will roll forward or backward against the parking pawl in an automatic, or 1st/reverse gear in a manual transmission. SCH-I535
I've always used the handbrake (parking brake), since I learned to drive in a time when few automatics existed. The licence examiners always tested you on hill starts. As a bonus, I've also had a life-long habit of handbrake starts at the lights, with my foot ready touching the gas pedal; it's a rare day when I don't get a couple of car lengths on everyone else, while they are still shifting their foot from the brake. GT-I9300 ?
I've always driven a manual, the Prius is my first automatic and I've only had it for a week and a half now but my left foot will still look for the clutch while my right hand goes to put the invisible key in the ignition. I always use the park brake. Even though I love the technology of the Prius I don't trust a button to keep my car from rolling even on flat ground. Maybe it's because I spent so long driving a manual (13 years) but I use a park brake. My dad used to always tell me to park my manual cars in gear so they won't roll and I've seen people do that and not use a park brake but I always parked in neutral and used a park brake.
Using multiple methods, e.g. parking gear + parking brake, seems more redundantly reliable. If one fails for some reason, the others will still be in effect. Feels that tiny bit "safer" if someone bumps you. (Whether it actually is..)
I've also experience parking brakes worn to the point of being unable to hold the car on the available sloped parking spaces, so would never leave the transmission in neutral. Especially in places with no curb in which to turn the front wheel (a backup I use less consistently).
If ever I was on a hill and questioned the reliability of the park brake with the gear in neutral I would put it in a low gear, 1st or R for a fail safe.
I've been around long enough to learn to not wait for signs of trouble before using fail-safes. Trouble has a nasty habit of not issuing advance warning.
Well, this has been interesting. And somewhat validating. Because I swear no one I know uses a parking brake at all ever for any reason at any time. I don't get logic that says, "I've been driving (or living or whatever) for 93840293 years and ________ has never happened therefore it probably never will." I have never been in a car (or house) fire, but I still have fire extinguishers. I can think of lots of simple things I do just out of habit not as the result of something bad that's happened before but because it seems like a good idea. I get when people say, "meh, I don't think much about it." Not so much, "never happened before, so probably never will."