YouTube ADS! :-( - Browser Support / Web Compatibility - Brave Community
https://community.brave.com/t/youtube-ads/500303

以下をカスタムルールとして追加する (in brave://adblock, custom rules)
youtube.com,youtubekids.com,youtube-nocookie.com##+js(json-prune, playerResponse.adPlacements playerResponse.playerAds adPlacements playerAds, streamingData.adaptiveFormats.1)
youtube.com,youtubekids.com,youtube-nocookie.com##+js(json-prune, playerResponse.adPlacements playerResponse.playerAds adPlacements playerAds, playerResponse.streamingData.adaptiveFormats.1)