YouTube is fantastic but it's a video platform, all you're going to find there are videos.

If I need to find a business or product page, I'm not going to look on YouTube. Same if I need to find a driver download, or a PDF manual, or the local weather, or information on a historical event, or....we'll, you get the idea. They just do videos.

Similarly Reddit has a lot but it's mainly centered around discussions of things. I use it as a very valuable resource, but similar to the above, it's not where I go when I'm not looking for the one thing they do very well - discussion.

It sounds as if the main thrust of this idea isn't that Google (or a search engine in general) is any less vital in daily web life, but rather that for some things you can go straight to the more centralised source and search there. E.g. if I want a video I'll search on YouTube, rather than searching Google for aggregated results from many video hosts.

In that sense Google is slightly less relevant sure I agree, but only a little bit, and only for very specific things.