I agree completely. The story shines heavily on Maxi's issues and her background, but we don't actually see much from Riftan's pov and his upbringing. Yes, we are aware he lost his parents young, was raised by mercenaries his entire life and was shipped into one battle after the other for his kingdom. But what we do know is before they got married, he met Maxi (even if she doesn't quite remember it) and she became his shining star in a cold dark world. His anchor. And like he said, he suffered with loving her and never having her for 3 years until he managed to gain enough power and prestige to be able to be on the level of a count to ask for her marriage.
And he's finally got her, but even so their marriage hasn't been the easiest. He still gets shipped off to fight in wars because he's one of, if not the strongest warrior wedon has currently. So he's often away and then he's also having to run his city as the leader, in his mind, he already has to suffer with so little time with Maxi that it physically pains him.
Then this whole matter where she snuck into a war zone. And yes, she was extremely helpful to have, but her use isn't what Riftan cares about, he cares about her wellbeing. In his eyes, as long as Maxi is safe and out of harms way, he doesn't care about anyone or anything else; and that is part of his problem because it does lead into the controlling behaviours that people see as an issue.
But what people at present need to understand is, Maxi is reckless because she wants to prove her worth to those around her, and her being a mage is tied to that. People forget, Riftan had to see the state Maxi was in after the monster raid, the fact that they have also just lost their child, and then the fact Maxi was taken by her father and beaten before his eyes. As a woman, I can see how that would be terribly overwhelming to have to deal with.
And now, Maxi is trying to gain independance (Which she is entitled to), but in this state, I think Riftan hasn't actually had the time with everything going on to process everything that's happened and it's making their poor communication skills even worse than normal.
To me, I think Riftan does see that it's beneficial to him, to keep his position, his prestige and his life he tirelessly spent a decade curating, but I think he's also just tired. Tired of having to listen to a kingdom who uses his strength, tired of being looked down upon by the nobles and tired of not being able to be by his wife's side especially now that they've lost that child; but like I said, we don't know how Riftan was actually raised, but something has clearly gone off because his first reaction to conflict is to shut down, be authoritative and push his narrative until he gets what he wants.
It's childish, yes, but we know very little about the life Riftan has lived to understand things we've got no knowledge on; and since we get little perspective from Riftan about his true feelings and his life, people are quick to assume he's just the toxic, obnoxious asshole who's abusing the fl, Maxi.
Like let's be real, we saw Maxi's reaction to the miscarriage, but we never actually saw Riftan's. Time hasn't gone by much since they lost that child and too much has happened since, and I genuinely don't think Riftan has had the time to process that he lost the child and I have no doubt a lot of this anger is because he blames himself for a lot of Maxi's problems. Not noticing the abuse, not being there for her like he should be, not pulling her back from the war like he wanted to which in turn lead to the miscarriage. I think Riftan is struggling with so much pressure at this point and his first instinctive reaction is to lash out, because he's used to battlefields and not discussions - and because Maxi and Riftan are opposite in this fact, it's leading to a lot of assumptions and miscommunication.
But Riftan isn't the only one to blame, like you said, Maxi holds some accountability too, because while it's her right to want Nornui if she wants, it's also true she never once consulted him about Nornui, when her innitial reason for going was to protect Riftan. They both want to protect the other, but fail to communicate properly their intentions and so it leads to these arguments we keep seeing as of late.

i feel like the book is heavely on Maxi’s POV so we cant really know what Rift is thinking. Just as much as Maxi wanted Rift to trust her and stop coddling her, I think she needs to trust Rift as well. I dont think she actually see her husband as a reliable man that can bring the duke down. She can be independent but she needs to accept kindness and helps too. She needs to see why it hurt him if she leaves him. And tbh i feel like even without the princess sugesstion, Rift can win those trials simply because if he is not a knight anymore, the country will be in a danger and the king will do everything to keep him in the country.
If Rift joins another country, it will be a threat to the kingdom. And if there is another monster attack, who is more reliable than him? So yes, I think he can win against the duke if Maxi just trust him and dont feel like she needs to solve everything.
I think she had a lot of opportunity to prove herself, and she did. She grow confident and become more mature. But I thought after the miscarriage, she would understand that at times she needs to prioritise her safety too. I mean, from Rift pov, if you suddenly saw your beloved one in a middle of battlefield, with harsh condition, and monster outbreak, where you can die anytime, you think he will not get angry? She even lost a baby. He is in constant state that he failed to protect her. So I think Maxi needs to understand the balance as well.
I know people are saying Rift is bad at communication, but the same goes to Maxi.