Yep, way off topic (when are we never off topic) Reels was Instagrams answer to TikTok and other short form video services (anyone remember Vine?).
And when TikTok started running into disruptions and fears of being shutdown over the last 4-5 years, for reasons I won't get into here, and Reel started adding more features and accessible to more demographics, people started to use the feature more and more until its become more dominant with the masses. Now TikTok is still more popular, especially with Gen Z, but Reel is a very competitive number 2.