Earth is not a Harlem Globetrotter basketball spinning around on a finger.
The simple answer to your question why I believe is because this is what all the evidence has shown.
The word you use – spinning – is designed to indicate the earth is like a spinning top whizzing around and around at high speed. This is not true of Earth. Earth is rotating very slowly. Imagine a soccer ball on a table that turns around once every 24 hours. You could stare at it for a long time and not notice it move. The earth rotates half the speed of the hour hand on a clock. Can you see a clock’s hour hand move? It’s moving twice as fast as the earth is rotating.
So no. The earth is not spinning. It’s rotating very slowly. So slowly that there’s only a barely measurable difference in your weight at the equator than at the poles.
When we say it “spins” at just over 1000 mph at the equator it misleads some people to think that is so fast that things should go flying off into space. Think of it in terms of revolutions per minute (rpm).
Circular saw blades have an rpm of 3,000 to 50,000. Things fly off them. Cars sometimes have RPM gauges that measure RPM in the thousands. In the image below, this car redlines when the engine has an RPM of 7,000.
The rpm of Earth is 0.000694 RPM or about about 1/2 of one thousandths of an RPM.
Things don’t fly off something going just over 1/2 of one thousandths of an RPM. On the gauge below that would register as zero.