Are you talking about a car without power steering, or a car with failed power steering? Because I remember being quite surprised how hard it was to steer a car rolling downhill after I turned off the engine (I thought it would be smart to conserve fuel, did not realise how unsafe that was).

It's gotten progressively harder over the decades because both steering wheels and steering ratios have gotten smaller as the reliability of power steering systems has improved. I think many people would have a very hard time controlling a modern car in the case of a power steering failure.

I am talking about a car with failed power steering. It is very hard to steer when moving slow, not so hard when moving. Presumably this could vary depending on vehicle mass and other factors but I do notice that both you and the person who replied to you with an incorrect assumption both made it, despite having to use your muscles.

Modern cars have crap suspensions/steering geometry for unassisted steering. This is a side effect of the geometry that helps keep their wide tires from making them wander all over the road. That said, it's only a marginal increase in effort. Modern cars are just fat. An Altima curbs at about the same weight as a base spec 2wd pickup that would have come with manual steering in the 80s and the Altima has a much higher steering ratio.

I think he is talking about the former. I've also had power steering fail on me and it took everything I had to get home. And I was ~2 minutes from home.

It also depends on the size of the car. I drove late 1990s Geo Metros and Ford Aspires without power steering. (I worked for a car rental agency.) It wasn't a big deal because the cars were tiny, but I think I would have struggled if the big pickup trucks had manual steering.