Nope, it wouldn't take a whole lot to get the numbers to start going down (compared to other currencies).
Yes it is not the strongest currency, because not all people are using it, not all people know that this currency exist. So conpared to old currency like paper currency or even gold are stonger than bitcoin I think. But if everyone are starting to use this, I vet this will be a strong currency. Stronger than any other altcoins.
There can be multiple different factors other than how many people are using and how many people are aware of it to measure a strongest currency. I mean to say the concepts are more important to conclude a currency is stronger or not and not just the user base. This way I am very confident and believing bitcoin must be the strongest currency so for in human history.
Because we had never got such a decentralized system with the all economical development. This type of new revolution concepts makes bitcoin as strongest a currency in my opinion.