Facebook offers all those things as part of Facebook.

Google offered a lot of totally unrelated things, from a phone OS to a video site, a search engine, and a social network which did incorporate some stuff on its own (hangouts and photos were well integrated and not really a problem as far as I can tell).

Suddenly introducing connections across all those different sites, so your mail contacts end up on your phone, your Youtube posts on Google+, and identities that you want to keep separate get merged against your will, that is stupid, harmful and a betrayal of their users.

It's not really to do with what the products are in a narrow technical sense, as to do with what the social context of their use is. After all, that's what makes a social network.

In particular, when people came to gmail in the first place, they were using it as an email service. When they came to youtube, it was as the world's largest collection of videos. They did not want these conflated.

You could list all those items for Yahoo and for AOL as well. But Youtube is distinctive in offering a huge collection of searchable videos. You name it, it's there, until it gets taken down by contentID or made unavailable in your country. Can you even search for videos on Facebook?