There could be several reasons why your traffic has dropped. One of the common reasons is a drop in keyword rankings. This could be due to many factors such as lack of keyword optimization, keyword cannibalization, increased competition, lack of fresh and relevant content, or lack of high Domain Authority (DA) backlinks.
A new Google Algorithm update could also be a reason for the drop in rankings. It's best to keep on top of Google updates and make necessary changes before they release the actual update. If you've been affected by an Algorithm update, you'll need to familiarize yourself with what it is and how it affects your website, then start working on the improvements in line with the update.
Another reason could be issues with your Google Analytics (GA) & Google Search Console (GSC) data not showing in the platform. If your traffic data isn't showing on the platform, try disconnecting and reconnecting your Google account within the platform. Also, ensure that you've connected the correct account and that your Google account is showing data.