Einstein uses the idea of space-time deformation to explain the characteristics of gravity, y so that, he mixes concepts and sensations that are far from necessary depth, logic and critical physical reality.

The idea of hole

In first time Einstein uses an ancestral sensation, erroneous and lacking of real consistence, which is the sensation that the holes attract mass.
This in erroneous because a hole made in the roof doesn't attract us; neither a hole made in a closed wall can produce any attraction on us.
If in some case a hole executes an attraction on us is due to another force that acts through the hole, as for example a strong air stream.
A hole by itself is nothing, and nothing it is not a force.
This way if we make a hole in the floor, it is not the floor that attract us, but the gravity of the earth.
On the other hand, a hole is the antithesis of matter: It is the lack of matter.

Idea of the deformation of the space-time

The idea of the deformation of the space-time neither represents an unsuitable explanation. If matter compresses or expands the space-time that surround it, then this space-time alone will be deformed, with more or less density of space-time, but this deformed space-time will stay stopped without motion; here alone dense space-time exists.
Say, this dense space-time doesn't have any type of motion, but alone more density.
This case, if we take an apple from outside of this field, and then we introduce the apple inside this field, the result must to be a deformation of the apple, say, the apple decreases its apparent dimension.
But the apple will stay static, without motion, because the compressed space-time doesn't have motion.

Energy and forces: Laws and characteristics

On the other hand, the physical laws of conservation of energy and characteristics of forces are against and deny the Einstein postulates on the gravity explanation.
The question is very easy and strong.
Let me remember the Newton formula of forces: force = mass x acceleration. f = m.a

This way if inside any gravity field is situated an object that acquires some acceleration, then here must to have the three anterior elements: object = mass; acceleration; and force = gravity field.
Say, gravity fields are physical fields of force with concentric direction.

So, as principle and law of conservation of the energy, if any acceleration exists - also must to exists the force than impel that acceleration.

The "tricks" of Einstein

I understand that our dear (and admired by his intuition) friend Einstein used in many of his postulate practical examples to make us understand that postulates, but I think that in those examples was the tramp or thick to make us believe what that scientifically wasn't completely acceptable.
One of this trick is the one exposed in the up drawing, where is represented an elastic mesh with two spheres, a smaller one and a little one, where the weight of both deform the mesh creating a rolling gradient that attracts them mutually.

Logically, the trick is that in the empty exterior space, where the gravity in null, the deformation in not produced and then the spheres don't weigh neither deform.
The deformation can be produced where an exterior field of gravity exists, as in on our earth, (as in the blue arrows of the drawing)

Conclusion about gravity

Taking in mind the anterior revision, with object of simplify and give an easy demonstration (but strong) of what gravity is, here we go to use simple physical laws as the Conservation of energy, and the inertial and forces laws (1 and 2) of Newton to define the consistence and definition of Gravity.

"If any object freely left inside a gravitational field acquires any acceleration provoked for this field, this is due to that the field is or contains the necessary force to produce the acquired acceleration by the object in accordance with the physical laws of conservation of energy, and the inertia and force laws of Newton."

This way, if force = mass x acceleration, f = m . a

Then in the case of the freely object left inside the gravity field, and for the acceleration would be produced, these anterior three parameters or elements must to exist: force, mass and acceleration.
And certainly we have these three parameters:

1.- The mass is the object freely situated.
2.- The acceleration (toward the centre of the gravity field) is the acceleration taken by the object.
3.- The vector of force with concentric direction is (of course) the gravity field.

This way, and as fundamental principle of the energy conservation, supported by the Newton laws of inertia and forces, we should establish that:
"It is impossible the existence of any acceleration without any force that can produce it"

"So the gravitation is a field of force with concentric direction".

This way here is postulated that the possible space-time deformations aren't forces able to execute any type of motion, but more or less suitable paths or roads for which the objects can move more or less easily depending of the true applied forces.

On the other hand, this question seems to be very interesting in some examples:
For instance: The apple of Newton.
If from the tree apple an apple falls, then this apple must to travel some quantity of space, till the floor; also this apple acquires some acceleration.
Then this acceleration must to be produced by a force, say the gravity force that Newton contemplated.