First a small recap:
Bitcoin is a currency.
1 BTC = Sat 100,000,000
Total Possible BTC = 21,000,000 (Due about 2140)
Current Mined BTC = 18,750,000 (approx.)
Current BTC Price = $40,604.36
Current Sat Price = $0.00004060436
Take a look at the Sat price: $0.00004 ... Not much use to anybody right? Now if the value of the Sat was at $0.04 then on a day to day basis, it would be useful. Think in terms of the dollar and the cent or UK pounds and pennies. The numbers after the '4' are still needed for making microscopic valuations similar to 1000th of a cent and so on.
So why is this important? Nakamoto picked the number of Satoshis to 1 BTC to be 100,000,000. A figure any higher would be a waste, save for mathematics the last digits would never be used (as a currency) and any smaller number and there would be a shortfall, the missing 10th of a cent so to speak ("Where's my missing pen top!") :)
Incidentally, if the price of Bitcoin was: $1,000,000 then 1 Sat would equate to $0. 01 !
With the above analysis I think we've still got a long way to go! :)