There are several reasons why lowering bounce rates & increasing engagement rates are important for your SEO:

When visitors are more engaged with your content, it naturally leads to higher conversion rates on your website, whether it is more leads or sales. Visiting more than one page on a website can indicate that a user is interested in the content and wants to learn more. This journey could lead them to eventually becoming a customer.

While the bounce rate metric is not considered a ranking factor, low bounce rates have been found to be correlated with higher rankings. This could mean many things, including that the content of these top-ranking websites is of high relevance, and high quality, as well as engages the visitor to lead them to other valuable content.

The bounce rate metric is useful because it can highlight potential issues on the page, such as any issues with content, user experience, page layout, design, or copywriting. It won’t give you the exact answer, but it flags up pages where further investigation is required that could lead to identifying what the real issue actually is. After fixing the issue, the bounce rate can be closely monitored over some time to see if the changes have lowered it.