I'll try to offer a simpler analogy of how that works.

Camp A on the side of a mountain is full of hikers. There is another empty campsite B on the other side of the mountain. And there are two possible paths between A and B - over the mountain or straight through a tunnel.

You order (apply voltage) the hikers (electrons) to go to camp B. While most are still packing, some hikers have their packs ready almost instantly and head out. Few of them go to the path leading to tunnel, few go towards the mountain pass.

When the next batch is ready to go, once again few will go towards the tunnel and few will choose the mountain way. However, the latter group will get stuck as the previous mountain guys will be seriously slow trying to get up. So a queue will start to form.

When the next batch is ready to go, they will see that there is a queue on one of the paths and will (almost) all choose the easy way where none of the previous hikers got stuck.

Similarly, the electrons don't in some magical way feel that the path will be harder. They are simply stuck between a bunch of previous electros that have hard time going that way so in the juncture they redirect to the route without the traffic jam.

The main difference between electrons in electrical paths and hikers on hiking paths is that all electrical paths are initially already full of electrons so the next electrons will instantly observe which path has trouble moving forward.

I'll try to offer a simpler analogy of how that works.

Camp A on the side of a mountain is full of hikers. There is another empty campsite B on the other side of the mountain. And there are two possible paths between A and B - over the mountain or straight through a tunnel.

You order (apply voltage) the hikers (electrons) to go to camp B. While most are still packing, some hikers have their packs ready almost instantly and head out. A few of them go to the path leading to tunnel, a few go towards the mountain pass.

When the next batch is ready to go, once again few will go towards the tunnel and few will choose the mountain way. However, the latter group will get stuck as the previous mountain guys will be seriously slow trying to get up. So a queue will start to form.

When the next batch is ready to go, they will see that there is a queue on one of the paths and will (almost) all choose the easy way where none of the previous hikers got stuck.

Similarly, the electrons don't in some magical way feel that the path will be harder. They are simply stuck between a bunch of previous electrons that have hard time going that way so in the juncture they redirect to the route without the traffic jam.

The main difference between electrons in electrical paths and hikers on hiking paths is that all electrical paths are initially already full of electrons so the next electrons will instantly observe which path has trouble moving forward.