as for me, i made Karg as my first DnD character when i was in secondary school. when i joined the US servers several years after launch i was a little miffed to find Karg had been taken. Worse was my rogue Thunderfoot, he was taken by a lvl4 fighter than in all the years since is still a lvl4. So someone had the same name as one of my main characters yet they don't even play that character now. it's irritating but that is how it works.
then there is my guild, The Legends Guild. on the now closed european servers the fountain in the harbour had a list of all the founding guilds. in there was the guild called Legends. that is my guild, it has existed since first beta. when we made the choice to migrate to the US servers we had no hope of reclaiming our name as by then the game had been running for years. so we are now called The Legends Guild. none of us particularly like it, but it's the best we could get in such an old game
what you are getting upset about is something almost every gamer has faced when trying to make a character. it is common among almost every online game where character names need to be unique.
to lighten the mood here is a little webcomic about a generic MMO (ie it takes inspiration from lots of MMO's).
as you can see it is one of the first things gamers expect to encounter. you got lucky on Wayfinder as it is a very poorly populated server making the chance of finding your name a lot higher. now that you have tried to make a character on a server with an average population you've run into this most common of problems.