I think people would only say Yen is Geralt's true love because that is the only long lasting relationship they saw in the books, if the author of the books dedicated say 4 books to Yen being the love interest of Geralt and 4 books to Triss being the love interest of Geralt, then i think there would be a majority of the belief that Triss was the true love. Luckily we have the games which give people the chance to look at two different relationships - the one of Yen which includes the books and the one of Triss which includes the previous games. I still fail to see how Geralt and Yen can live happily ever after and of course this isn't a Disney story but Geralt and Yen have always been through so much including all the bad stuff that it is easy for a viewer to intepret those events as meaning she is the true love but to Geralt - how much can he take before Yen goes too far.
The game has perfect examples of the comparison between Yen and Triss, like Yen will engage in black magic while Triss won't, Yen will use sarcasm when talking to Geralt while Triss is unlikely to use sarcasm. Yen is more powerful and cares about those dear to her meaning she will go through hell to protect them, while Triss is also like that but cares about all the other mages and has a more sympathetic view of others. Yen is also more likely to throw Geralt through a portal if they have an argument. None of what i just said means Triss is the better option (to me she is) but it is just what the person believes are the better qualities.
Triss has her flaws, she does seem too selfless at times, but ultimately what the events in the game show is that Triss is torn between what she wants and what is the 'right' thing to do, breaking up with Geralt is one of those, she even says to Geralt when they first meet "Six months ago, Triss Merigold parted with someone very dear to her". She wants to be with Geralt, but Geralt knows he has to find Yen to see if he still loves her, instead he gets somehwhat a cold reaction with Yen saying she didn't pursue him because he and Triss made a great couple. Now that is part of her sarcastic personality but all that time you spend away from someone you loved only to keep up your reputation as a cold, strong willed person just seems wrong and there are many examples through the game where Geralt could of said enough is enough especially now that he has seen what it is like to be with someone else that is quite different from Yen. On the other side of the coin, however you could argue that Geralt is use to it and he admires that about Yen because he sees her as something of a challenge, so yeah that is just my opinion as to why he has developed more than feelings for Triss which leads to a bond and love that his past can only influence and make him compare the two special women in his life (apart from Ciri of course) in a relationship.
---------- Updated at 01:04 AM ----------
I agree, it is one thing to say Triss is very important to the story of the game, yet it is another to actually show it. I think CDPR are listening to us as they have stated that changing/adding/fixing some things are manageable, others not so much. I really hope they do add something, it just seems like a complete waste to build up this great character in the previous games and have her so important to the main character, only to run out of ideas on what to do with her especially in the second half of the game.
---------- Updated at 01:08 AM ----------
It would of been one of the highlights of the game, i still remember Phillipa's comment to Triss in W2 "Triss, stop thinking with your ******", Phillipa is a great character especially when she dives into Geralt's personal life
