When going for the Wonder achievement, which requires you to meet 10 different players, you will have quite a hard time if the player population is very low.

Checking the wiki of the game revealed a little information that may come useful to people trying to get the achievement "fast".

"If you are on your first journey, you cannot meet white robes , as they are more experienced and might interfere with your first experiences in Journey. However, if you don't wear your white robe and go in your red robe you have the chance to travel with first runs."

The companions page of the wiki contains many little pieces of information but this is the most useful one for people trying to finish the achievements. Here it is: https://journey.gamepedia.com/Companions

The white robe is awarded to the player that has completed the Transcendence achievement. You can change robe in the chapter select in the sunken city, where you can also find an overview of the symbols that you have collected.

In conclusion,