I’m skeptical anytime someone’s first argument about why to do X is “it’s best practice”. When their second argument is also “it’s best practice” that skepticism deepens significantly.

Yes and no. "Best practices" (if they are indeed best practices, e.g. SOLID) one violates at their own peril. I liken it to an apprentice learning to paint. Once one has mastered the rules of the game, then one can become Picasso and know which rules to break.

Completely agree. "Best practices in our industry" is usually just used to dodge responsibility, or as a cudgel to impose your view on others.