Last I tried writing custom rules for Facebook was years ago, but they did have proper aria attributes, and uBlock origin does have selectors for text content. These are from 2020:
facebook.com##span:has-text(Suggested for You):xpath(../../../../../../../../../../../../../../../../../..)
facebook.com##div[aria-label="Sponsored"] span[aria-label="Sponsored"]:xpath(../../../../../../../../../../../../../../../../../../../../..)
facebook.com##div[aria-label="Sponsored"]:xpath(../../../../../../../../../../../../../../../../../../../..)
