This post tests various embed blocks:

https://twitter.com/WordPress/status/1057136472321613824
Twitter,  wide width
https://youtu.be/ex8fMxXJDJw
YouTube
https://www.facebook.com/6427302910/posts/10156380423617911/
https://www.instagram.com/p/BpmueLLgEn_/?utm_source=ig_share_sheet&igshid=1hcxphic7p9e2
https://wordpress.tv/2018/10/14/kjell-reigstad-allan-cole-how-we-made-our-first-gutenberg-powered-theme/
WordPress TV, full width