I went down the world’s shortest rabbit hole, I began wondering how flat earthers deal with the concept of gravity and I found this answer:
Spoiler!
As pointed out in Terence Kreft's answer, there are those that think it’s displacement. This is easily the most wrong answer, as he explains.
There are those that think that gravity on a flat Earth is the same gravity as on a spherical Earth. Depending on whether the flat Earth is an infinite plane or is plate shaped, this has varying levels of issues.
Then there’s “universal acceleration,” the idea that gravity doesn’t exist and the Earth is accelerating upward at approximately 9.8 m/s/s. This actually comes the closest, but still has two big issues. First, at that rate of acceleration, we’d have exceeded the speed of light long ago, even if you’re a young Earth advocate.
The second issue is that the perceived acceleration of gravity of the Earth isn’t consistent, for two reasons. The first reason being that the Earth’s mass isn’t uniform enough to keep the acceleration uniform. The second reason being that acceleration towards the center of the Earth is a fraction of a percent slower at the equator than it is at the poles. This is because the centrifugal acceleration caused by 1 revolution per day at a radius of 6371 km works out to be 0.03369 m/s/s, or about 1/3 of 1% of the actual acceleration due to gravity at sea level.
Now, while that doesn’t sound like much, it works out to be about 2 km/s/day. So in order for the Earth to be experiencing acceleration rather than gravity, the poles would have to be accelerating by 2km/s per day faster than the equator, and you’re going to have a hard time explaining how the Earth would still be flat after even a single day of that, since at the end of the first day the poles would be 86,400 km higher than the equator.
And for the record, this issue tends to falsify (think counterindicate, not disprove) all the flat Earth assertions, even when they claim it’s the same gravity that a spherical Earth would have.
Displacement theory is wildly dumb.
Flat earth having equal gravity as a round earth makes no sense, the density of different surfaces would vastly change the effect of gravity in different locations.
Universal acceleration is also wild, what force exerted on earth would cause uniform acceleration? Does terminal velocity not exist? Would the earths mass not change as pieces of the planet would fall away with no gravity to hold it in place?