I agree with @acediscowlng that it’s a bit of both.
Sometimes I just like a “x character”/ trav ship purely bc it scratches my brain in good way.
Most of the time I feel most characters are/become a lot more interesting if you don’t ship them with traveler and instead as friends or sth more nuanced.
Also often it just doesn’t suit their character to fall in love with trav, or end up in relationship with them.
Usually characters have a lot more interesting relationships between other characters than with trav.
There are also some characters like Ayaka (my queen) where her having crush on trav is basically canon; but where her also realizing that they are not meant for each other bc of their differing lifestyles and self discovering herself through her mothers story and thus accepting that they will never be together but still deeply loving trav for the support they have her in hard times and making it possible to learn about hers mother life presents very satisfying narrative to me.
And so there are some characters where them falling in love with trav but not ending with them is very fitting option in my mind. After all for some characters trav had very big impact on their lives (like Furina, Ei, Ayaka, Nilou, Wanderer, Jeht), and for some almost none at all (like Chiori, Kirara, Mika, Dahlia).
As a multishipper it doesn’t really bother what do you like more bc at the end of the day, if you are able to convince me by presenting the scenario where it would make sense for any of the characters to fall in love and end up in relationship with trav, I’m sold on it.
My only caveat would be making Traveler actual character instead of self insert. Part of the fun of shipping trav/any character is also exploring the reasons why trav would fall in love with this particular person.
