That is really a point!
However, for American stocks they are fortunately small: slightly more than €0.5 per trade.
We announced that we set a stoploss by -20%.
If we, for simplicity, assume that we also take profit by +20%, we need the probability to win to be at least 53% just to stay breakeven. Indeed: 0.53*97.56*1.2 + (1-0.53)*97.56*0.8 = 98.73
But we think the chances in this case are even better than 53%.
Moreover, the ETFs are also not “free” in the long run.
Have a look at https://letyourmoneygrow.com/2017/10/01/etfs-dont-save-indeed-increase-costs-long-term/