Logical necessity.
Because the alternative is to presume everything spontaneously emerged from nothing, and for no reason. And that is just logically absurd according to everything that now exists.
By the way, that "singularity" is just a fancy word meaning "some incomprehensible state that we know nothing of".
I disagree. The error, I think, is in supposing that "everything spontaneously emerged from nothing," but this doesn't really have to be true. For sure, at the very beginning, in the first picosecond (10−12) of cosmic time, during which currently established laws of physics may not have applied. But as this early mush began to cool, the emergence in stages of the four known fundamental interactions or forces—first gravitation, and later the electromagnetic, weak and strong interactions; and the accelerated expansion of the universe due to cosmic inflation—begin to become explicable by modern science. Not directly, of course, but by working through the equations at higher and higher temperatures.
Tiny ripples in the universe at this stage are believed to be the basis of large-scale structures that formed much later, and at this stage, there really doesn't have to be "creation" going on at all — merely the laws of physics playing out so that over the next 370,000 years, various kinds of subatomic particles are formed in stages. These particles include almost equal amounts of matter and antimatter, so most of it quickly annihilates, leaving a small excess of matter in the universe.
At about one second, neutrinos decouple; these neutrinos form the cosmic neutrino background (CνB). If primordial black holes exist, they are also formed at about one second of cosmic time. Composite subatomic particles emerge—including protons and neutrons—and from about 2 minutes, conditions are suitable for nucleosynthesis: around 25% of the protons and all the neutrons fuse into heavier elements, initially deuterium which itself quickly fuses into mainly helium-4.
By 20 minutes, the universe is no longer hot enough for nuclear fusion, but far too hot for neutral atoms to exist or photons to travel far. It is therefore an opaque plasma.
The recombination epoch begins at around 18,000 years, as electrons are combining with helium nuclei to form He+. At around 47,000 years, as the universe cools, its behavior begins to be dominated by matter rather than radiation. At around 100,000 years, after the neutral helium atoms form, helium hydride is the first molecule. Much later, hydrogen and helium hydride react to form molecular hydrogen (H2) the fuel needed for the first stars. At about 370,000 years, neutral hydrogen atoms finish forming ("recombination"), and as a result the universe also became transparent for the first time. The newly formed atoms—mainly hydrogen and helium with traces of lithium—quickly reach their lowest energy state (ground state) by releasing photons ("photon decoupling"), and these photons can still be detected today as the cosmic microwave background (CMB). This is the oldest direct observation we currently have of the universe.
From there, of course, you can begin to see chemical reactions, and although we haven't found the actual mechanism yet, abiogensis leads to creation of self-organizing and replicating forms of life -- and that part, we know quite a lot about.
So, a "creator" may be a "logical necessity" for that first picosecond -- or it may not. Science might yet discover something about the Planck epoch (oddly named for such a short period of time).