You lost me with the subtitle.
“Subjective” is an admission that you don’t have an argument.
And you don’t. Senior developers are people who think about what they’re doing, who plan and design. The rest are people who slavishly follow compulsions like speed optimization or methodology fads like agile and scrum, or who think unit tests are important
Junior developers talk about refactoring and technical debt and stories. They’re compulsively obedient and conforming.
Subjectivity doesn’t have anything to do with it.