That was also strongly discouraged on older cars and only possible with big steering wheels and good grip. Just move very slowly and the turning becomes really easy even without assistance (and which is what you were thought when this was still a thing in countries with required driving lessons).
Are you sure? Fully “steer by wire” vehicles with no mechanical steering link are already in production. The Tesla Cybertruck is the most well-known example.
Toyota/Lexus has also been demonstrating steer-by-wire for a while (Lexus RZ), and it will apparently ship in consumer vehicles later this year.
https://www.drive.com.au/news/toyota-lexus-steer-by-wire-sys...
(In some aspects the US automotive regulations are actually stricter than in Europe. For example, in Europe there are some vehicles (eg: Audi) where the wing mirrors are replaced by screens/cameras, but this is not permitted in the US. Adaptive matrix headlights are also not allowed in the US.)
Electronic throttles became widespread much later than the 80s. Pop the hood of common 2000s economy cars and you’ll find a mechanical throttle linkage.
All 90s cars I've had or worked on had a real cable from gas pedal to throttle body.
In an electric power steering system there are steering angle and torque sensors that know what direction the wheel is turned an how hard it has turned, and this is connected to an electric motor that powers the gears to move the steering rack.
There are still regulations in place that require a mechanical connection to the steering wheel and rack, but try and turn the wheel with the car off and see if your wheels move... But when the car is running when you turn the wheel you're just a voting remember in the system.
There are no such regulations for throttles. Pretty much every car since the late 80s has electronic throttle control and there are no mechanical linkages from pedal to throttle body.