>Who is competing with gmail? Please include market share and revenue in your analysis

Outlook, Yahoo, (insert a long list of Chinese providers here), Yandex, Fastmail, Zoho Mail, Hey, Protonmail and so forth.

All of the above have actually managed to capture a decent share of the market, and there are many more.

>This is more defensibile than the YouTube argument, there is Rumble and Vimeo for instance. But again, What is the market share and revenue for YouTube vs these other “competitors”?

Instagram and Facebook are also huge in the same space. I'd guess that Akamai is even bigger.