No, the planet is not increasing its velocity steadily at 1g. The force of gravity on Earth is relatively constant near its surface, resulting in a steady acceleration of approximately 9.8 m/s², which is commonly referred to as 1g (g = 9.8 m/s²). This acceleration due to gravity causes objects to fall towards the Earth, giving the impression of weight.
In contrast, an orbiting spacecraft or satellite is in a state of free fall around the Earth. The reason we don't experience the same free fall as objects in orbit is because we are supported by the surface of the Earth. The ground exerts a normal force on us, counteracting the force of gravity and preventing us from falling freely.
When we are standing on the Earth's surface, the ground exerts an upward force equal to our weight, thereby canceling out the downward force of gravity. This contact force between our bodies and the Earth's surface creates the sensation of weight and keeps us from falling freely.
In the case of an orbiting spacecraft, it is essentially in free fall around the Earth. The gravitational force acting on the spacecraft provides the centripetal force necessary to keep it in a stable orbit. This allows the spacecraft to continuously fall toward the Earth due to gravity but with sufficient tangential velocity to miss the surface and keep going in a circular or elliptical path.
So, the key difference is that we are supported by the ground, which counters the force of gravity, while an orbiting spacecraft is in a state of free fall around the Earth due to its tangential velocity matching the curvature of its orbit.