This is very inaccurate because the trades execute immediately. Very rarely are you able to actually execute a trade immediately.
That's true even in the stock market. Stock market simulators need to build in a slight delay to be accurate.
More often in bitcoin you are putting in speculative buy and sell orders at a fixed price and they execute as soon as someone is willing to sell/buy at that price. It could trigger in minutes or weeks (or never) depending on how the market moves.
Also, I'm not sure if the prices here are agregate accross multiple exchanges but in reality the book of orders needs to be deep enough in your exchange to actually execute the order.
If the deal is in another exchange you would have to transfer your coin to take advantage of it and at current network speeds by the time the coin gets there your deal will be gone.
The most real world variable missing is taxes. In short coins held less than a year can be taxed at a 39% rate on the high end and a trade on a coin held more than a year is 20% (again on the high end). Even those numbers vary on the traders tax bracket (income).
It is significant, especially when you don’t know and the IRS audits you adding late fees, penalties and maybe legal fees.
However the trick is in accounting for trading costs and dealing with order execution, particularly if you are reliant on maker fees only to remain profitable.