Instagram does not share any of its ad related earnings with its users who post contentInstagram earned $20 billion in ad revenues in 2019 - much higher than YouTube's $15.1 billion. Instagram reportedly accounts for more than a quarter of Facebook's ad revenue in 2019. According to reports, Facebook made a total of $70.7 billion in revenue from advertising during the year. The user count of Instagram hasn't been updated since 2018 when it reported 1 billion users.
Facebook acquired Instagram in 2012 after a cash payment of $1 billion. Instagram could also be more profitable when compared to YouTube as the video sharing site shares most of its ad related earnings with creators. Also, YouTube's video-focused approach could possibly mean higher streaming costs.