I've found that listening and asking questions is the key to accepting other people's architectural choices.
Why do they insist on A over B? What trade offs were considered? Why are these trade offs less threatening than other trade offs? What previous failures or difficulties led them to put such weight on this problem over others?
Sometimes it's just ego or stubbornness or routine¹. That can and should be dismissed IMO. Even if through these misguided reasons they choose the "right" architecture, even if the outcome turns out good, that way of working is toxic and bad for any long term project.
More often, there are good, solid reasons behind choices, though. Backed with data or science even. Things I didn't know, or see different, or have data and scientific papers for that "prove" the exact opposite. But it doesn't matter that much, as long as we all understand what we are prioritizing, what the trade offs are and how we mitigate the risks of those trade offs, it's fine.
¹ The worst, IMO, is the "we've always done it like this" trench. An ego can be softened or taken off the team. But unwillingness to learn and change, instilled in team culture is an almost guaranteed recipe for disaster