There are no cars where the brakes are powered by the drive belt. Not even the very old hydropneumatic Citroëns, with a belt-driven hydraulic pump - because they could go for 20 or 30 miles on the stored pressure in the brake accumulator.
If you can't control a car with dead power steering, you can't control a car. Power steering only makes a difference at parking speeds.
If you blow a belt or one of another thousand things go wrong, and the engine quits, then there’s no power to drive the steering.
In a relatively large vehicle - say, a VW Amarok - power steering provides significant moment on the steering that is immediately and unexpectedly removed when motive power is lost. While the car is arguably controllable, I was shocked at how difficult it was for me to maintain directional control when it happened to me, and I’m a pretty big guy.
In fact, in my case I just stalled it. The twin turbo 4cyl engine had a very steep power curve and it was easy to pull the clutch at just the wrong RPM, before the turbo kicked in. Especially if I had been driving something else. So - there’s a failure mode triggered by simple ergonomics. The combination of an unexpected stall during acceleration also presents a heavy driver workload, as I discovered more than once.
The brakes are also powered by the engine and it requires very significant additional force to stop a large car whose engine has just quit unexpectedly. I’m not sure that everyone who drives such a vehicle could recover if the failure happened, say, at a busy intersection.
All I’m saying is that we shouldn’t be nostalgic about ICEs. There are far more failure modes for them, all of which can lead to engine failure and subsequent controllability issues.
My car is a second-generation Range Rover that weighs around 2.5 tonnes. Without power steering it's very hard to steer at parking speeds, and absolutely no different at all above about 20mph.
No vehicle has brakes "powered by the engine". I'm not sure if you're maybe not quite explaining what you mean clearly there.
I don’t know what to tell you. Even a cursory search makes it clear that power assisted braking is a thing.
When the engine stops, no vacuum. No vacuum, no assist. The brakes in most of the cars I’ve driven become substantially more difficult to use when the engine is off.
Okay, so in a car with vacuum assist, you have full braking power for several applications of the brake. Once the vacuum in the servo is exhausted, the brakes still work but will need a much harder press on the pedal. If the brakes become hard to use the second the engine is off, your brakes are fucked and you need to get the servo and master cylinder replaced.
Many really modern cars have gone back to the old WABCO-style electric pump that will pressurise the braking system as long as there's power in the battery, because that whole thing plays more nicely with hybrid drivetrains.
Until now you said that no car has power brakes, now you’re saying well they do have power brakes but they keep working when the power’s gone. I really don’t understand why you’re arguing with me.
But it is all beside the point. It’s easy to point out problems with BEVs because they’re new, but ICEs are far more mechanically complex and are therefore also subject to many kinds of failures. Simply because they have fewer moving parts, complete loss of power in a BEV is far less likely than in an ICE. This is why I said that we shouldn’t be overly nostalgic for ICEs.
Perhaps you’re just overly focussed on my throwaway line about “blowing a belt” - ICEs can also fail from a damaged cam, valve, pushrod, crankshaft, distributor, piston, timing chain, injector, air intake, turbo, fuel pump… I’m not really sure what your point is other than to nitpick at my example of one of the literally dozens of complete power failure modes of an ICE.
Let’s not get overly nostalgic for the incredible mechanical complexity of ICEs.