I have seen a similar blog by Indi (indi.ca) a long time ago. However, it's true because the mass of the Earth isn't distributed evenly. Varying surface topography and the continuous movement of water cause different parts of the globe to have more or less mass than other regions. Thus obviously the Gravity changes.
Since 2002,
NASA's twin GRACE satellites have mapped Earth's gravity and a NASA animation can be viewed from here.
https://nasaviz.gsfc.nasa.gov/vis/a010000/a011200/a011234/3655-540-MASTER_high.mp4
Warm colors (red, orange, yellow) represent areas with strong gravity. Cool colors (green, blue) represent areas with weak gravity.
Below is a photo of our area.
The broad gravity low in the equatorial Indian Ocean south of Sri Lanka is the largest and most striking feature in the gravitational field of the earth. The most negative long-wavelength free-air gravity anomalies are found there and the sea surface (geoid) lies more than 100 meters below the best fitting ellipsoid. A model of the lithosphere and upper mantle is proposed which accurately predicts the observed free-air gravity and geoid elevation. This model is consistent with bathymetry and sediment thickness data and suggests that the crust south of India currently floats as much as 600 meters lower than would be expected if the region were isostatically compensated. This residual depression of the crust is apparently confirmed by observations of ocean depth. An uncompensated depression is consistent with the presence of a mechanical wake left in the upper mantle behind India as it traveled toward Asia.