I've done travelled in various areas of Spain, China and Russia (and had studied Japanese years back), and have been able to do rough communication with all of them to some level, but ... when you are doing it, you realize how much you don't know. No, I can't just read any level of book I want, can't understand all the news programs (or the local ramifications), couldn't go see a theatrical play, couldn't conduct business, etc. BUT... the few phrases and words I know, apparently I sound good enough that people have mistaken me (for perhaps 30 seconds, until I keep going) for a native speaker. (well, not in china!)
I remember feeling quite humbled that the 4 year old at a mcdonalds in China was still more 'fluent' than I was as an adult. That gave me a lasting impression, and deep respect for people who move to other countries, develop new lives, and learn a foreign language and culture. I'm not saying I could never do it, but... it's immensely difficult.
Those skills can't even be assumed in native speakers.
For example: https://nces.ed.gov/naal/
These hyperpolyglots are supposed to be high IQ.
If you have a high IQ, but look like a low IQ illiterate in a dozen additional languages, then I'm afraid you're a phonyglot. This is because there are ideas that you can think but cannot say in those non-native languages; and if someone else were to say those things for you, you wouldn't understand what they are saying.
Could they understand a complex news story about economics and finance in all those languages? Read a novel? Write an essay on a complex topic?
I'm skeptical.
You could be mistaken as a native in six languages if you just make small talk with a perfect accent and intonation.
Someone who really knows a language has a (passive) vocabulary of some 25,000 words. A proper hyperpolyglot should have 11X then, once per each language. Yeah, sure!