Is it really that hard to conceptualize fractions of BTC? .1 BTC ~= $280 and .01BTC ~= $28
Doesn't seem all that difficult to me
Is it not that it is difficult, it is just that we need to adjust the reference because it is getting cumbersome. No one says "I have 100 cents" when they mean to say they have 1 dollar, nor they say "I have 0.001 thousands". The reference is the unitary dollar and it is easy.
Countries with high inflation often go/went to print absurd bills like "500,000 X$" or something like this. They eventually cut off these extra irrational zeroes on the right to keep the reference easier.
With a deflationary currency like bitcoin the same happens but contrariwise, so we need to "cut off" the extra zeroes on the left in referencing the currency, from time to time. It gets cumbersome to say "I have 0.032532 BTC". If we start to fix satoshies as the reference we can append M, K in front of it. So 0.032532 BTC becomes 3.2532 Mega satoshi, or just 3.2532 Msat. As the coin goes in a deflationary trajectory, soon we will move to Ksat and then just satoshi. This is very easy as everybody is familiar with these measures of magnitude by using computers.
The advantage is also psychological. The same way the countries with "500,000 X$" bills give a false impression it is a lot of money, referring to BTC in terms of the inflationary dollar give the appearance of 1 BTC being "something" which is expensive as hell, while the trully indivisible minimal unit of value is the satoshi. Wow, just one coin costs almost 3 thousand bucks? Wow. That's the current impression.