It might help to read up a little on this topic. Here's an article near the top of the web search results:
https://www.electricbike.com/torque-sensors/. Note that PAS just stands for Pedal Assist System, so you can't assume that a bicycle advertised with "PAS" doesn't use a torque sensor.
The down side with that article is that it's written with the very common bias towards PAS in general. A typical clue is
A throttle makes an ebike feel more like a motorcycle than a bicycle, and many Americans prefer that.
Many Americans have the option to discover that a throttle works pretty well, unlike Europe where I understand it's prohibited, but the notion that it makes your bicycle "like a motorcycle" is common but misguided. I don't know, there are reportedly different kinds of throttle functionality, but I believe what you're likely to get these days is a voltage control, which essentially governs speed. I set my throttle, in effect, for say 15mph, and then - yes, if I don't pedal, the motor will carry me along at 15mph, maybe a 200 watts depending on grade etc. On the other hand, if I pedal at about 100W, the motor will just fill in with the required 100W. It
is pedal assisted, it just allows you to easily choose, separately, how much you want to pedal, and how fast you want to go. I've ridden a motorcycle, it isn't anything like this.
I almost always pedal fairly vigorously, because I want to (the main exception is when I'm trying to deal with my toeclips or something.) I don't need a mechanism to make me pedal when I don't want to, and I don't have much confidence that something like that would really achieve any worthwhile object. If people want an easy ride but are forced to get "pedelecs", then those systems will eventually be designed to allow "mime" pedaling, if they aren't already. Who cares.
[edit] As you may gather from the above, the effective use of a throttle is an extra skill that people don't have just from having learned to ride a bicycle. Not much of a skill, but it's more than nothing. PAS is arguably, nothing - you just pedal, and the motor pitches in. So it makes great sense for rental bicycles, for example, like the thousands of green rental bicycles that litter the streets around here, and in general for people who just want a little extra boost and don't want to be bothered with a throttle. What's better, depends on the user. What's unfortunate is that the clearly superior torque sensing PAS mechanism is more complicated and expensive, given that from my perspective at least, it's aimed at a more casual rider. [/edit]
