Three main reasons for that:
a) Maia is, imo, a much better example of a kind protagonist. Celehar is a typical decent person who does not stand out in this way from an enormous crowd of fantasy progatonists.
When Maia is first told he’ll be emperor, before he gets to court, when he first sets foot on the airship that will carry him to court, he pauses to reassure the crew of the airship. He thinks to do that even though this stunning news has just been delivered.
When the coronation takes place, at the end of a very, very long day of fasting and ritual, when the princes take their oaths of fealty, he both sees and responds to the distress of the Prince of Thu-Athamar: “Neither blame nor gilt belongs to you. Do not hold them so closely.”
These are just remarkable instances of empathy, compassion, and kindness. Moments like this absolutely pervade The Goblin Emperor. In contrast, Thara Celehar is much more focused on himself, on his own feelings. This doesn’t mean he isn’t a compassionate person. He is. But he’s not like Maia.
b) Thara Celehar is too self-effacing and will not stand up for himself.
Maia doubts himself at least as much as Celehar. He is constantly thinking of himself as unworthy, ignorant, clumsy, inarticulate, whatever. But he stands up for himself when it’s important. Celehar just does not. This is frustrating.
c) This is the first book of a longer story. This is true even if Addison never writes another book in this series. Witness simply does not feel finished.
Celehar is shown as doubting himself and self-effacing and unwilling to stand up for himself because — this is the feeling I get — his character arc is going to involve moving toward a stronger, more confident stance over the course of a longer story. That’s how it feels.
This is even more true because the hint of romance in Witness is just that: a hint. This story reads like the first part of a grief-and-recovery story and the first part of a romance. In every possible way, Witness feels incomplete.
While I would love to see a true sequel to The Goblin Emperor, the story is much more complete as it stands.
So, Witness, well, I enjoyed it. But for me, it’s an order of magnitude below TGE.