One may have many science fiction or fantasy projections of how physics might be. In the real world physics and physicists use mathematical theories as tools to model experimental observations.
Two landmarks guide the modelling of data at present .
The validation of Quantum Mechanics as the underlying framework that describes with great accuracy the microcosm of elementary particles and predicts with great accuracy future behavior in new experiments.
The formulation and validation, to a great extent, of the Standard Model of particle physics.
Number 1) has lead to the realization, in contrast to your hand waving shadows science fiction scenario, that all classical theories are emergent from the quantum mechanical level of fields and particle interactions. This emergence can be rigorously derived using mathematics, not words. Even before quantum mechanics it had been mathematically shown that Thermodynamics, a beautiful classical theory with its differential equations and postulates, emerged from statistical mechanics, the mechanics of large number of particles, again in a well derived mathematical manner.
Number 2) is within quantum mechanic and quantum field theory, but in addition the standard model uses the mathematics of symmetries arising from group transformations and gauge invariance. These symmetries under transformations exist in classical electrodynamics , but find their great usage in quantum electrodynamics and the behavior of elementary particles in forming the standard model of particles.
The success of the standard model and the symmetries it obeys guides the thinking of most physicists about General Relativity ( a classical theory) which also has similar symmetries . The goal is to have one unified model for all interactions at the quantum level, thus the proposal and search for the graviton as the corresponding particle to the photon of the gravitational interaction.
So it is the mathematical consistency of the validated experimentally models that describe the elementary particles that leads to the expectation of a quantized gravity. Call it a beauty postulate.
Another strong reason to expect quantization of General Relativity is that classically it has infinities, like the Big Bang and the black holes, singularities where values predicted to be measured go to infinity. This problem for electrodynamics was solved by quantum mechanics: the 1/r behavior of the potential between two charges lead to infinities/singularities which disappeared with the quantum mechanical formulation of quantized energy states. One may say that the classical "nature abhors a vacuum" has been transformed to "nature abhors infinities". In general terms it is the Heisenberg Uncertainty Principle connected to the probabilistic formulation of quantum mechanics that is the tool to control infinities. Thus one expects that a quantization of General Relativity will dispense with infinities/singularities.
For all these reasons I do not know, am not aware, of serious physicists working with assumptions of the order you imagine. There already exists a mathematical framework that accommodates both the group structures of the standard model and a quantized general relativity , string theories. In plural because as yet no unique successful model exists to be chosen out of a plethora of possibilities, but theorists are working on the problem. There do exist less popular researches on gravity which still quantize it but asking for discrete space time ( as loop quantum gravity) or 't Hooft's deterministic model but I believe anybody working with gravity accepts some form of quantization, mainly for the reasons stated above.