Facebook is over-moderated and delivers extremely low-quality content. Their Instagram division got a bit better and is the only relevant competitor, however Reels is still highly unusable in Search form if you're looking for new, quality, and unique niche content.
If you're 18 years old and want to learn to fix a plumbing leak quickly, TikTok can deliver you a high quality video with the learning aspect done in 30-60 seconds. YouTube, you have to sit through 10 minutes of SEO / filler content, skip to 3/4 the way, and watch the process slowly because they prioritize 15-20 minute videos.