I agree with you! I saw a lot of comments about Joseph and I was worried, but even though I'm only on chapter 90, I LOVE EREZ!!!! I really feel like they have great chemistry and he's so fucking charming. Joseph isn't bad, but Erez captivated me.
Not only that, I found Erez's personality refreshing for a ML. He was cute and laid back not too overhearing. Also, even before there a finality I always on his side because I felt that no matter what he does Josheph will never really be equal to Keira. He'll always be a step behind her because of their inherent power dynamic as Master and her knight. I stand by your point that she isn't someone who needs contestant protection. His mentality from the very beginning has been to "serve her with loyalty" even after he realised he liked her romantically. It's very hard to change that dynamic and mindset.
He is genuinely a nice guy but I genuinely didn't feel any chemistry or that she was the right fit for him. He'd have always felt sort of insecure around her from a 3rd person's pov if they were to date.
idk about y'all but i fucking loved erez, and sure, joseph was cute and all, but he was just so overprotective towards the mc and that ticked me off a little. she's not some dainty princess who needed protection 24/7. i mean, yeah, that's his job, but i guess it was a personal preference. i am a little bit sad that he wasn't the ml, because obviously he's he's really sweet, but he definitely deserves someone better, and erez and her had really great chemistry.. even though i was at still chapter 80+, my eyes were so set on erez, because it's not usual that mages gets to be the final love interests in isekai stories, i guess. so that was nice too.