Do a google search for Tesla dyno graphs. You’ll see the power is virtually flat while the torque decreases steadily. It’s constant power output, not constant torque.

Any “constant torque” would be due to the fact that at low speeds you’re traction limited so only a fraction of the cars power can be used.

Once you’re no longer traction limited, the torque will steadily decrease and power output will be flat.

This is a Tesla S P85D on a dyno. Notice the torque peaks (at 864 ft-lb!!!!) then steadily decreases. The power is nearly perfectly level just above 400hp for the entire second half of the run.

https://www.pinterest.com/pin/297096906643419592/

Internal combustion engine horsepower numbers a little bit misleading. The numbers they tell you are actually "peak" horsepower. A 2022 Corvette makes peak 490 horsepower at 6,450rpm. This means it makes less horsepower at every other rpm, most notoriously at low rpm's.

An electric motor makes its peak power ALL the time.

Let's say you're watching a fast moving object. First it's here [X ]. Then it's here [ X]. If you're playing a video game and it moves that distance between frames, that's what you'll see. If you're watching a movie, you'll see something more like this [XXXXXX ] followed by [ XXXXXX] because there's motion blur. That's why a 24fps movie will seem much smoother than 24fps video game. It's because it's capturing the motion blur.

Now video games could simulate motion blur, but it's computationally expensive, and easier to just make many more frames and let your eyes/brain fill in the blur.