Architectures are like opinions; everyone has one that’s based on their own biases. Sometimes it’s a dedication to using only open source solutions, a specific brand of public cloud, relational databases, you name it. These biases are often the driving factors that determine what solution you employ and how bad or good those choices are.
The issue is that when you choose components or technology based on a bias, often you don’t consider technology that’s better able to meet the core requirements of the business. This leads to an architecture that may approach but never get to 100% optimization.
Optimization means that costs are kept at a minimum and efficiency is kept at a maximum. You can give 10 cloud architects the same problems to solve and get 10 very different solutions with prices that vary by many millions of dollars a year.