If your sole goal is to have a homelab that self-hosts services, I completely agree. I'm speaking for those who are interested in developing their skills and knowledge, and believe that building something with AI somehow does that.

I'll agree to disagree on it not being applicable. Having fundamental knowledge on topics like networking thru homelabbing have helped me develop my understanding from the ground up. It helps in ways that are not always obvious. But if your goal is purely to be better at your job at work, it is not the most efficient path.