A higher Quality Score generally means lower costs and better ad positions for the same bid, which makes it worth actively managing.
Relevance Between Keyword, Ad, and Landing Page
The tighter the match between what someone searched, what your ad says, and what the landing page delivers, the better this scores.
Expected Click-Through Rate
Ad copy that speaks directly and specifically to the search query tends to earn a higher click-through rate than generic copy.
Landing Page Experience
A slow, cluttered, or irrelevant landing page can drag down Quality Score even when your keywords and ad copy are strong.
Next step: Use the Page Speed Checker to rule out landing page speed as a drag on your Quality Score.