Which voice assistant speaks the most languages, and why?

Contrary to popular Anglocentric belief, English isn't the world's most-spoken language by the total number of native speakers -- nor is it the second. In fact, the West Germanic tongues rank third on the list, followed by Hindi, Arabic, Portuguese, Bengali, and Russian. Surprisingly, Google Assistant, Apple's Siri, Amazon's Alexa, and Microsoft's Cortana recognize a relatively narrow slice of those. It wasn't until this fall that Samsung's Bixby gained support for German, French, Italian, and Spanish -- dialects collectively spoken by 616 million people worldwide. And it took years for Cortana to become conversant in Spanish, French, and Portuguese.