The problem with random generators
Most online palette generators produce adjacent swatches by spinning a color wheel. The output looks fine in a screenshot but collapses when you try to apply it — the lightness values conflict, the contrast ratios fail WCAG checks, and nothing maps cleanly to a primary/secondary/surface role. Starting from a concept instead of a random seed produces better results because mood and use case constrain the hue range before you touch a slider.
