This collapsing electron orbit issue was a stumble stone for the last major classical Rutherford model of an atom. According to the classical electrodynamics, an electron accelerated by a central force should emit radiation and finally collapse on the nucleus.
The Bohr model of an atom was the first major quantum atomic model, addressing this electron collapsing issue. It has been postulated that just particular energy levels are allowed, where de Broglie matter wave of an electron forms a standing wave along its orbit.
The Bohr model was significant progress in its time, predicting many observations. But it was later abandoned for its various shortcomings. The major issue was addressing the electron orbital angular momentum and problems with its zero value ( the quantum number $\ell=0$ ).
It was replaced by the quantum model based on the Schroedinger's wave equation, that came with the concept of orbitals.
Later came the Pauli(Schroedinger-Pauli) equation addressing spin and then models involving Special relativity as Klein-Gordon equation or more famous Dirac equation.
The consequences of the Dirac equation are predictions of antimatter before it was observed ( specifically of a positron ) and natural integration of phenomena of quantum spin, that was until than rather an ad-hoc addition to non-relativistic models.