I have see an argument by a flat earther that says the disk earth can explain gravity by the earth moving through space at a speed of 9.8 m/s/s. For this to be true the earth would have to be accelerating continuously at 9.8 m/s/s. Assuming this, the downward force on everything would increase rapidly, and within hours everyone would be crushed to death. Do you have any other explanation for gravity?