Gravity is the attraction between objects with mass. The attraction is greater if the objects are more massive. The shape of the object practically doesn’t affect the magnitude of the attraction provided the objects are spaced far enough.
Flat-Earthers like to perform the ball-and-water ‘experiment’. They spray water to a ball, then observe the water does not stick to the ball the same way seawater stays on the surface of the Earth. They would conclude that ‘gravity does not exist’. They are wrong. The spherical shape of the Earth (and the ball)does not cause gravity,
They used a ball as a model of the Earth because they don’t understand how gravity works. The Earth and the ball are both spherical, but the spherical shape does not cause gravity. Their hypothesis is wrong. The force of gravity does not come from the spherical shape, but the mass of the involved objects. In this case, Earth’s mass is far greater than that of the ball. Thus, water is attracted more to the Earth than to the ball.
In fact, it is the other way around: the spherical shape of the Earth is the result of gravity. If a celestial object is massive enough, it will tend to be spherical.
And if they are taking this seriously, they would at least attempt to control the gravity from the real Earth, so that it would not affect the result of the experiment. One way to do this is to perform the experiment in free-fall, like in a zero-g plane.
From the way the ‘experiment’ is currently done, all we can conclude from it is that the spherical shape is not the source of gravity. And we already know that.