https://www.techradar.com/news/youtube-gaming-goes-web-only-from-march-as-google-kills-standalone-app

YouTube Gaming was launched in 2015 to give video game enthusiasts a place to watch and engage with game streamers, chat with other gamers, follow game pages and to provide a home from game specific video content.

While game-related videos are quite popular on the platform (with over 200 million daily viewers, in fact), the YouTube Gaming app is not. So Google has brought the app's most important features over to the main YouTube web platform, with plans to permanently close the standalone app from March next year.