I hope you want me to explain a bit further. Or if you don't, just ignore this.
This is the idea I am pointing out. Example you bought 100 Xcoins (at a cheap price) of course you only receive 99.9 because of the 0.1% fee. Then you had sold the 99 at (of course) a higher price leaving 0.9 untouched. Due to price fluctuations, you were able to buy again 100 Xcoins at a cheaper price making your total Xcoins to be 100.8. This time you can sell the whole 100 when it hits your desired price leaving only 0.8 Xcoins unsold. When this continues, there will come a time that you'll get a balance of numbers without decimals.
This will basically apply for traders not for one-time exchangers.
I would also like to point out that when selling coins in binance, the fee will not come from the coin you are selling anymore but to the btc (eth, bnb, usdt) you are receiving.