The periodic table that is known and widely used today was not created instantly.
It took several different scientists and professors more than three decades to fully develop it. The first tool to show a pattern between the known elements (at the time) was created by Alexandre-Emile Béguyer de Chancourtois in 1862. He created a cylinder called a “telluric screw” that contained vertical groups of three elements with similar properties on each side.
It was a very incomplete model, and had several mistakes in it, but was the first recorded attempt to organize the elements. Two years later, John Newlands created the law of octaves. This stated that if elements were arranged by atomic number, every 8 elements they would have similar chemical and physical properties. Finally, the first full periodic table was attempted by Dmitri Mendeleev and was published in 1869. This table organized elements by atomic weight, and utilized the law of octaves to arrange similar elements in columns known as groups.
With elements yet undiscovered, Mendeleev decided to leave gaps in the periodic table where he predicted the elements would fit. This would prove accurate, as three elements found over the next 15 years had the properties he predicted and were accordingly placed in the periodic table. What finally put the modern periodic table together, however, was the discovery of noble gases in 1894. When they were discovered, instead of creating doubt in the periodic system, it was incorporated as the eighth group in the table. Over the next 100 years, other elements would be found and included in the table, bringing it closer to completion, until the final four were synthesized and publicly released in 2016.
With this, the periodic table is considered “complete” so far. Thus, it can be said that an increase in knowledge does not correlate with an increase in the doubt of said knowledge.