High quality ratings for an ad can:
increase its average cost-per-click (avg. CPC) bid
be achieved with an increase in bid
improve its position
increase how often people click on it
Explanation:
Quality Score is an estimate of the quality of your ads, keywords, and landing pages. Higher quality ads can lead to lower prices and better ad positions.
Read more here: https://support.google.com/Google Ads/answer/140351?hl=en