I understand what you are saying, but I do not understand how that would be move convenient. People need to understand what a Bitcoin is and when we do this, you will confuse people. When first started with Bitcoin, I did a faucet thinking I was getting more than I was because it was in mBTC. It is just confusing for newbies.
No more confusing than grams and milligrams, or meters and millimeters.
If you're confused by all those, you better pay more attention.
Ah but if you have ever had physics or chemistry etc. you always use the SAME units because it avoids mistakes.
Physics tends to use mks - meter, kilogram, second. Chemistry tends to use cgs - centimeter, gram, second.
Using the same units for everything avoids accidental mistakes.
Hence why I am using BTC in my wallet even though mBTC would be preferred. Since the places I spend present prices in BTC then I should use BTC to reduce odds of human error when converting between the two, even though the conversion is always an exponent of 10.
It would be nice if markets presented prices in mBTC but very few do, BTC is what the market has chosen.
'Tis true that scientific equations are constructed so that all components use the same units or subunits.
It does more than prevent accidental mistakes - it enables anyone to use them without checking what subunits are required for each variable value. All you need to know is the system used (e.g mks)/
With the current discussion, we're talking really simple conversions tho. Not algebraic, just arithmetic.
The operations involve only decimal point shifts (3 to the right, 3 to the left etc) and a simple multiplicative factor to get to/from fiat.
As you say, you wouldn't mix subunits even in the arithmetic calculations (like say adding btc to millies, or adding btc to dollars); you normalize the units first.
For these arithmetic operations, the units don't matter. The only requirement is to not mix units.
So your 'same units' can still be btc or mbtc in any one calculation. The subunit chosen doesn't affect the calculation (like it would if the units needed to be exponentiated in a physics equation for example).
