It's said in the screenshot. To get the screen reader-accessible text, you need to press a specific button (instructions are displayed before the scrambled text), and then your browser will be computing some complicated puzzle for a few seconds in order to "unscramble" the text

This puzzle is computationally expensive, so while it doesn't fully protect against bots, it drives the cost of scraping way up. And since this scraping is done to somehow profit from it, driving the cost up is definitely a deterrent