Off the top of my head, I can name several "first"-based approaches. Do any of these ring a bell? Mobile first, content first, API first, user first, design first, experience first, modeling first, security first.
For far too long, experts in these various realms have caught the attention of communities by coining these terms. They speak to the vulnerable: people who have ultimately been burned by not applying the best practices of whatever is being sold. But, that is an altogether different problem than what is ultimately being sold.
What is being sold is the need to put something first. This doesn't seem wise to me. Putting one of these items first implies deprioritizing the rest of the needs. The only relevant "first" I see is the user. Their needs should be first. The actual solutions will likely be a combination of all "firsts." Because users ultimately don't just want a "first", they want your solution to be well rounded. No "first" should be prioritized over another unless it has direct relevance to meeting a user's needs.
As such, "firsts" need to die. We need to be well informed for all of these considerations to best meet our user's needs. That is what they expect. Putting one "first" before another is not only short-sighted, it's ineffective. The experts who position a "first"-based strategy should be positioning themselves as experts in the specific discipline. But, that's certainly not as sexy as making a claim that one discipline should be first and regularly exploring this.
We would be wise to not buy into any "first"-based strategy as opposed to leveraging our collective experience to gleam best practices in a given discipline. To me, this speaks more to the value of the message being delivered. Again, these people are experts in one discipline (maybe more) but we need to stop giving credence to putting one discipline before another. You need to be good at them all to be effective.