The amount of monthly contributions has doubled in the last four years alone, from ~7k to ~14k commits per month. Why did I take six years as a reference? Because 2020 is the year nixpkgs really started to pick up traction, and the growth has been almost linear ever since.
Your argument only holds if I were to say "it grew to its current amount of monthly contributions in 2020 and then stayed constant, without growing any further."
But also out of those 6y the core team did not exist for ~5y, apparently. How is it a highly ignorant reaction?