For online ads? Sure you can make that case.
Their business in the end is based on delivering relevant content. If there is a market for the traffic Google refuses to host, then there are probably market opportunities there.
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.