If it were hypothetically possible to travel close to the speed of light, the crew inside the spacecraft would not be crushed by the acceleration itself. However, they would experience a number of other significant effects due to the high speeds involved.
According to special relativity, as an object with mass approaches the speed of light, its relativistic mass increases, and the energy required to accelerate it further also increases. As a result, it becomes increasingly difficult to accelerate an object with mass to reach or exceed the speed of light.
Assuming the spacecraft could somehow overcome this limitation and achieve speeds close to the speed of light, the crew inside would experience time dilation and length contraction. Time dilation means that time would appear to pass more slowly for the crew relative to an outside observer. Length contraction refers to the phenomenon where objects in the direction of motion appear shortened from the perspective of the crew.
These effects could be quite extreme as the speed of light is approached, potentially making the journey seem shorter for the crew compared to an observer outside the spacecraft. However, it's important to note that reaching the speed of light itself is considered impossible for objects with mass, according to our current understanding of physics. The theory of relativity imposes certain limitations on how fast objects can travel based on their mass and the energy required to accelerate them.