Steem account creation "fee" is actually a minimum bandwidth rate limit to signal the blockchain that said account will not have the available bandwidth to make transactions within the blockchain.
To understand this, we need to know how does the Steem Blockchain do away with transaction fees when almost every other cryptocurrencies has it.
This is because Steem transactions are based on Bandwidth rather than fees. It's why you can sometimes sees smaller account unable to post anything when the traffic is unusually high. And it goes back to why Steem Power is so important within the Steem ecosystem. Having higher SP is akin to paying more fees to the blockchain when you make a transaction. Imagine Gas in Ethereum but instead you have Gas Station. The bigger the more gas you can afford.
And so there is a point where the SP starts too low to qualify for any transactions since the blockchain will not recognize it. That "point" is the Account Creation Fee as seen in the blockchain (you can look at SteemDB.com) to get a live feed of it.
This "Fee" however is deceiving, because you actually need 50-100 times the amount paid to the new account to get it qualified for transaction. Which isnt all that much considering it's just 5-10 steem if you decide to fund the account entirely on liquid Steem. This Steem will be converted into the Steem Power of the new account.
There is actually so much technology within STEEM that it's so underrated as a blockhain compared to other with so much hype and so little substance. Just the aspect of Fee-less transaction alone would have killed so many other blockchain that vies to be the "cheap transaction" blockchain.
Not to mention 3 second blocktime, human-memorable addresses, huge scalability potential and so much more..