Assuming UX mistakes, the consequence is straightforward. There will be low conversion on the site. Accordingly, I recommend analyzing the site and looking for UX mistakes. Based on this analysis, you can build the correct hypotheses of user behavior on the site’s pages.
Basically, the search for UX mistakes is based on data: heatmaps, scrolling depth, moving the mouse cursor, and recording video sessions. First, of course, you need to see what the bounce rate is in the Google Analytics report.