How to use Vector3.Lerp but with a smooth movement without slow down and speed up

When you use Vector3.Lerp to move an object from point A to Point B, it speeds up at the beginning, and then it slows down at the end (and then never quite reaches the end either).

How can I use the same thing but without this kind of acceleration, just a linear smooth constant speed from point A to point B?

Lerp interpolates linearly between two vectors. It does not slow down or speed up. And, if you pass deltas from 0-1 it will always start exactly at the beginning and end exactly at the end.

I suspect you may be applying it by moving a transform a set percentage from its current location to a target location. This is not “incorrect”, but it will lead to the slow down movement you describe. To use it “correctly” to move with linear speed, see here: Using Vector3.Lerp() correctly in Unity — One Man's Trash is Another Man's Blog

you need use vector3.movetowards