You're actually right. So, this method might not be considered a long-term solution. The article I linked to is actually part of an online guide where I explain how to set up a company step by step. Readers currently at this stage don't yet have a mailbox (like a Google Workspace subscription with a custom domain). A few steps later, I'll explain how to use Gmail with a custom domain. Then, they won't need email routing. This solution is very useful in this regard.