How important is ui-ux experience for seo

The short answer to that is a definite YES.!
How good your website's USER INTERFACE AND USER EXPERIENCE UI/UX are, has a great deal of impact on the value of your site's SEO. As a good site with attention to detail and best practices in mind to be mindful of smooth webiste operations and transitions. Allows for a more seamless experience for the user and that accumulates into a good SEO score over all for the webiste. Also keeping in mind ADA compliance as that can be an even greater helper or can severally hamper your site's growth if it's not taken into account.
The best interactive website with great content is bound for success in it's SEO strategy.

That's a given. If a site is tough to navigate, or is unintuitive, it will hurt your site, as traffic will back off fairly fast. If you have a smooth user interface, and it's fast and responsive, and doesn't bug the users, you will have an easier time keeping traffic on the site.

That's a given. If a site is tough to navigate, or is unintuitive, it will hurt your site, as traffic will back off fairly fast. If you have a smooth user interface, and it's fast and responsive, and doesn't bug the users, you will have an easier time keeping traffic on the site.