Esperanto and "I am..."
In a lesson on verbs, "Mi sidas" is "I am sitting." Literally, it is "I sit" (present tense). How can Esperanto distinguish between the two? Can you use the verb "to be" (I am) plus the verb (for example, sit) to say, "I am sitting on the couch" instead of "I sit on the couch"?
Take a look here: http://esperanto.davidgsimpson.com/eo-verbforms.html.
It seems English is the only language (from the ones I know or know about) that uses the continuous tense so much. Some languages don't have it at all. In Czech you say "Sedím" which is really the simple present: "I sit" or "mi sidas". You could say "Jsem sedící" perhaps, but that really means a somewhat different thing, and you'd never say that. Still, Czech is not a language limited in scope. In fact, we have other constructs that aren't in English or other languages. No need to think of English as somehow deficient or limited in scope.
There's lots of times when it is very difficult to translate a precise shade of meaning from one language to the next. Sometimes you just need more words, or be satisfied with a slightly different version. For example the (somewhat archaic sounding) Czech sentence: "Příchozí vejda uviděl" means something like "The incoming person, while coming in, first saw (something)". In Esperanto perhaps: "Alvenulo enirante ekvidis", though I feel that really means that the person began to see while doing the entering, while the czech phrase would mean (as far as I would understand it) that the person began to see right after (or at the moment of) entering.
As a quick note: Turkish probably employs continuous tense even more. Most normal daily conversation is usually done using the present continuous tense. But that's probably because the equivalent simple present tense (which is called the "broad tense") is mostly used to express things that happen in much broader time-frame, or to emphasize a fact.
Apart form that, I fully agree with you that comparing peculiar constructs of a language against other languages won't help judging their "scopes". Again, Turkish has a very frequently used tense to express an event that supposedly happened but the reporter hasn't witnessed it by himself, so he can't be 100% sure. Yet, this never hampers other languages in terms of expressing stuff. English, for example, is doing just fine without that construct, and certainly not "limited in scope" due to lack of it whatsoever.