Had a tad of science in my youth.
My hypothesis, which you confirmed, is that gravity is not fully understood. There is the theory of a gravitational field, but its composition is not yet fully understood.
I suspect a nobel prize is waiting for the scientist that demonstrates the components of the gravitational field.
These notions IMO, all point to the need for research into gravity.
These days the Nobel Prize is awarded for explaining things like why we don't trust the used car salesman.
We don't know that it isn't fully understood. There certainly aren't any experimental results that contradict Einstein's General Theory of Relativity.
The reason we suspect that the gravitational field is quantizable is because every other force we know about is quantized. Electromagnetism is described well by photons, the strong nuclear force is described well by gluons, and the weak nuclear force is described well by the W and Z bosons. The problem with quantum gravity is that gravity is a spin-2 field (i.e., for every unit of momentum carried by the field, there are two units of angular momentum). Unfortunately, when you go and naively quantize a spin-2 field in 4 dimensions, the quantities you calculate are infinite.
As a matter of fact, there are only two spaces in which the calculated quantities from such a field can be finite: one space has 11 dimensions, and one has 26 dimensions. The "superstring" theories that have captured the attention of the press (and M-theory, which relates them to each other) are 11-dimensional theories.
But we can't discount the possibility that nature is just perverse, and gravity really does have a totally different structure from all the other forces. Perhaps General Relativity is all there is.
These notions IMO, all point to the need for research into gravity.
There are gobs of research going on in gravity, particularly in quantum gravity. Every time you see the word "superstrings", it refers to quantum gravity research.