Red, theory; black, fact.
Some of the paradoxes and weirdness of quantum mechanics can be dispelled if we assume that any particle that can be diffracted isn't really there: we are only looking at the center of spherical symmetry of a much larger, possibly cosmologically large, wave function. Furthermore, this center of symmetry is only an abstraction, like the north pole of the Earth. Like the fields that we impute to them, quantum particles would have a wave function amplitude that decreases asymptotically to zero with distance from the center, and thus would have no well defined outer boundary. I shall denote this lack of an outer boundary by calling particles or wave functions "expansive."
Elementary particles seem submicroscopic in size because the wavelength of the corresponding wave functions is often submicroscopic, which imposes a requirement for the centers of symmetry of two such "particles" to coincide with very great precision before an interaction can be observed. This would be the case if the default interaction were characterized by destructive interference almost everywhere, which only switches over into constructive interference when the centers nearly coincide. An assumption needed for further development of this theory is that interaction is contingent on the development of expansive constructive interference. (In this post, I confine my attention to scattering-type interactions.)
The common presence of accelerations in our universe combined with a finite speed of light might suggest that expansive wave functions would quickly fill up with incoherence, destroying their usefulness as explanatory causes. However, if there are no non-expansive elementary particles, we just have expansive interacting with expansive to produce every acceleration. Once you get entirely away from the tiny-electron idea, it is not at all clear that any incoherence could ever develop. Such may well occur to a limited extent under some conditions, however, but it may take more detailed mathematical treatments than I am prepared to carry out to characterize these conditions. One naturally suspects that Relativity theory is based on such limited incoherencies.
Two baffling kinds of experiment seem amenable to the big-electron treatment: diffraction of "particles" of matter like electrons, and entanglement experiments.
Electrons fired in a vacuum at a pair of closely-spaced slits, with a photographic plate situated on the other side of the slits, will produce a diffraction pattern on the developed plate consisting of alternating exposed and unexposed bands. These are interpreted as locations of constructive and destructive interference between "matter waves" emanating from the two slits under the stimulation of the electron beam. If the intensity of the beam is lowered to the point where only one electron is "in the chamber" at a time, thereby eliminating the possibility of inter-electron interactions inside the chamber, the diffraction pattern develops just as before. It merely takes longer. Now here's the weird part: all this could happen only if each electron goes through both slits at once! This is truly weird if we try to use the traditional tiny-electron picture, but much easier to visualize using the big-electron picture.
Entanglement of two particles that persists over distances measured in kilometers is also easier to understand if we remember that the experimental apparatus is itself made up of expansive wave functions and is therefore mostly overlapped with the two particles being studied throughout the experiment.
If all this is true, we live in a vast web of inter-validating illusions called the particle model.