I don't know your reality but literally anywhere in the 744 million users in Europe if you consider the technology literate average of internet users I guarantee that someone who is not even bilingual is precisely the exception.
I would hazard say the same is true in most of Asia and Africa perhaps less so in South America where Spanish/Portuguese are more monolithic.
A significant part of Africa, Benelux, The Nordics, a huge part of the indian subcontinent, most expats in any country, Canada...
Even if you live in a purely Monoglot country (And those are less common than people think), in absolute numbers it's a lot of people
I don't have any numbers but it seems plausible that the average user doesn't make an informed decision about where they consume their videos or which search engine they use. They buy a smartphone to connect to their family and friends, to learn and to use essential services.
Unfortunately the smartphone is not designed to help users with this goal. It is a medium for tech companies to shove garbage down the throats on people who are just trying to live their lives, and to perform the largest mass surveillance campaign in the history of mankind. Communication and connectivity is the Trojan horse used to sell the malware that the smartphone is.
This feature is designed for users who "don't know any better".
It's not that you have to be able to speak multiple languages, understanding several is still common.
[citation needed]