[sametmax]

I'm not worrying about killing diversity.

Languages are not static, english would evolve local features, variations, incorporate things from other languages, and adapt to specialized needs and creativity.

Some alternative languages would survive anyway. Some new may develop.

How do you think we got those many languages in the first place ?

The important thing is that all people have a root base they can use to communicate. And official one that is formalized, used systematically and taught globally. Not that we seek to eradicate what's goes beyond the root.

The important thing is that all can fill the same administrative forms, understand each others laws, debate ideas with equal strength, share books, consume remote news, discover other countries, etc