What could “leka darka achrina” mean? Isn’t the world round? Aren’t there boats? Two possible answers:
1. The gemara held (that reb chiya bar abba held) the world was flat;
2. It means a path of equal or substantially similar inconvenience.
Answer “2.” is much better, agreed. It does negate 95% of what people try to learn out of the gemara though…the world could always be flat…