Not sure if this is a silly question, but since we know that there exists plenty of viable information to support the theory of evolution, why is it still only considered a theory?
Because in the sciences "theory" means a framework in which empirical research can be conducted, experiments designed and interpreted, and data/results structured. The "theory" of evolution is a framework that forms the basis for entire fields of scientific research (e.g., evolutionary psychology) and guides and structures research in a vast number of fields (e.g., machine learning, linguistics, astrobiology, etc.). In the sciences, many theories are more fundamental than entire scientific fields, and evolutionary theory is one such example.
In general, the use of "laws" to describe findings in the sciences has been abandoned. Most of the "laws" in physics or chemistry or in the sciences more generally are now known to be false. Theories can and are often more fundamental than laws. In general, we do not bother to classify findings in the sciences in terms of laws, theories, etc., or even bother with such nomenclature. Quantum mechanics is a theory but is rarely referred to as such (and is distinguished from the slightly archaic term "quantum theory" because this can be and often is taken to include both non-relativistic and relativistic quantum field theories), embodied cognition is a theory although I can't remember it being referred to as such, most models are theories, and most theories are not precisely defined in any one way nor are they encapsulated by any one interpretation or understanding.
There are issues in evolutionary theory that have not been resolved, despite the virtually incomparable evidence for evolutionary theory and the basically unanimous acceptance among scientists of evolutionary theory. The theory itself has grown as our understanding of the processes it seeks to describe has grown. Darwin, after all, knew nothing of genetics, and the double helix structure of DNA was only discovered in the mid-twentieth century.