I've been sitting on this, primarily because I don't have a source I can point to that says what I've got to say, but since no one has bothered, I'll go ahead and try to get the discussion rolling. If someone else comes in with more info, I can adjust later.

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The sweet and short answer is: No, that's not how language works.

No language is better or more able at conveying complex ideas than any other language in any inherent sense. The problem is, of course, that many ancient languages did not have terms for many concepts that humans had not yet discovered at that point. This is not a limitation of that language, however, but rather, a limitation of the knowledge of the people who used that language. However, some languages, by nature of a large lexicon, can convey complex terms in fewer words or syllables, but that is because languages are not static constructs, but can change with time, including by adding new words as new concepts are invented. Remember, languages are nothing more than a set of symbols used to express ideas. For any language, if a new concept is created, then either a new symbol needs to be created to express that idea or a new grouping of already existing symbols needs to be assigned to said new concept. The limitation is not in the system of symbols that is used, but rather in the ideas those symbols are meant to represent.

Take, for example, the internet. English did not always have a term for the internet because the internet had not yet been invented (much in the same way that ancient languages do not have terms for many modern inventions). But despite that, one can describe the general idea using English terms from pre-internet times. If you wanted to go crazy, you could do it using terms exclusively from the 19th century (and using exclusively the meanings of those terms from that period). Granted, that would get a bit cumbersome, but you could do it. English of the 19th century is not inherently less able to convey complex ideas just because it doesn't have a word for the idea of the internet, it just takes a bit longer.

As another example, take a look at this monstrosity of a word: Fussbodenschleifmaschinenverleih. It's a German word (I know, right?) that means "Floor Sanding Machine Rental". Is German somehow more able to convey a complex idea (like a store that rents floor sanding machines) than English simply because German has one, obnoxiously long word for an idea for which English uses at least four words? I would argue not.

Now, if you're asking if some languages are better at transmitting information on a per syllable basis, rather than transmitting ideas generally without constraint of syllables or words, then yes, some languages appear to be more succinct, but again, that does not make one better or worse at transmitting ideas, complex or simple, more generally.