As someone who has personally dealt with files as large as 60K lines, I disagree completely. I believe instead that structure and organization should be added as a business and codebase scales. The problem I think most orgs make is that, as they grow more successful, they don't take the time reorganize the system to support the growth, so, as the business scales 100x in employee account, employee efficiency is hampered by a code organization that was optimized for being small and nimble.

It gets worse when the people who made the mess quit or move on, leaving the new hires to deal with it. I've seen this pattern enough times to wonder if it gets repeated with most companies or projects.

I do agree that microservices and/or modules aren't magical solutions that should be universally applied. But they can be useful tools, depending on the situation, to organize or re-organize a system for particular purposes.

Anecdotally, I've noticed that smart people who aren't good programmers tend to be able to write code quickly that can scale to a particular point, like 10k-100k lines of code. Past that point, productivity falls rapidly. I do believe that part of being a skilled developer is being able to both design a system that scales to millions of lines of code across an organization, and to operate well on one designed by someone else.