The reason why we don't typically observe wave-like behavior at macroscopic scales is due to a process called decoherence. Decoherence refers to the interaction and entanglement of a quantum system with its surrounding environment, leading to the loss of coherence and the emergence of classical behavior.
At the macroscopic scale, particles interact with an immense number of degrees of freedom in their environment, such as other particles, electromagnetic fields, and thermal fluctuations. These interactions cause rapid and uncontrollable entanglement, resulting in the suppression of quantum interference effects and the emergence of classical behavior. As a result, the wave-like properties of individual particles become effectively "washed out" or averaged over many interactions.
While it is true that the underlying particles and fields that make up macroscopic objects are governed by quantum mechanics, their collective behavior gives rise to emergent classical properties. This emergence occurs due to the overwhelming number of interactions and the statistical behavior of large ensembles of particles.
The transition from the quantum to the classical realm is a subject of ongoing research and understanding. Various theoretical and experimental investigations aim to explore the boundary between quantum and classical systems and understand how and under what conditions quantum behavior gives way to classical behavior.
In summary, while particles at the macroscopic scale are ultimately made up of quantum entities, their wave-like properties are generally not observed due to the rapid decoherence and the emergence of classical behavior resulting from interactions with the environment.