Until the recent fundamental change of making cars electric instead of run on gas, have there really been many other "improvements of a radical nature" since 1909? If you go back and you look at cars from that period they not only look like modern cars, they are made by the same companies. They definitely are less powerful, and yet they have similar miles-per-gallon efficiencies as many larger cars from recent years.
Why is "of a radical nature" the important part here, and who gets to define it? Is fuel injection radical? Seatbelts? Crumple zones? GPS? In 1909 a car had 35HP and could peak at 53MPH, and was an ultimate death trap in an accident. Hundreds of improvements, some more radical than others, led to the cars of today being better in virtually every way, including subtle ways nobody knew mattered at the time (like not flinging people out the windshield in an accident).
That phrase is important because otherwise it wouldn't be there: it is load-bearing in that quotation.
All of the things you mentioned seem like the kind of incremental improvements you get over an additional hundred years of iteration and improvement... but I think it is non-sensical to try to sell that refinement as as impressive as the burst of improvement and innovation you saw as cars were first being defined.
In practice, I think a lot of people want every individual thing we do to follow some kind of exponential or even linear growth curve, but it seems much more likely that everything follows a sigmoid curve: an S-shapes trajectory wherein after a period of slow improvements the actual meat of a particular innovation are really experienced during a much faster and almost explosive growth followed by a return to slow incremental improvements to wring out the last benefits (but never just becomes fully flat).
The reason why, on a whole, we see such great improvements in our lives is then because of the combination of numerous S curves from new paradigms that overtake the old and provide an illusion of smooth and continual progress.
Like, I do think the premise of "tech progress" slowing down is strange: in the past few years alone we've seen disruptive "radical" paradigm shifts occurring that have altered how people live their lives to a pretty radical extent--though if you wanted to discount anything that was catalyzed by political and medical crises I might be forced to cede my stance? like, looking back in 40 years, this might all look incremental as I guess a lot of it is still speculative--but banal things like word processors or even laptops, we're clearly pretty far past the growth phase of the S-curve, and so all the things we already have aren't really improving much anymore and likely never will.
Any given change to a car might by itself fail to seem radical - I agree, yet in the decades since 1909, how cars (and trucks) are used in our world has changed radically, and radically changed our world. Paved roads and freeways, gasoline production, the repair industry, and taking for granted that a person of ordinary means (in first world countries) has the ability to travel dozens of miles to work daily. Foodstuffs can get transported hundreds or thousands of miles and be edible. My parents didn't eat a green leafy vegetable from October to May as children, because such veggies didn't grow locally in Winnipeg.
Yes, there have been massive improvements. so much so that many people take these as a given. Here’s a small few off the top of my head:
- power steering (most people would struggle to drive a car without it)
- anti lock breaks
- suspension systems
- fuel injection
- multi gear transmissions
- airbags
Now that I think about it I’m not sure I’d put the change from gas to electric as more revolutionary than a number of these seemingly mundane improvements.
