For video-sharing platforms.

1. When you buy an Android phone there's a good chance that YouTube app is preinstalled.

2. If you search the net for "how to do XYZ" or for any song you'll get 99% video results from YouTube.

3. Almost every company/celebrity/influencer/... has a YouTube account and until recently (TikTok, Odysee, BitChute,...) alternative platforms (Vimeo, Dailymotion,...) were mostly a niche market.