The author, Jeff Geerling, is a very intelligent person. He has more experience with using niche hardware than almost anyone on earth. If he does something, there's usually a good a priori rationale for it.
Like what about the people who maintain the alpha/sparc/parisc linux kernels? Or the designers behind idk tilera or tenstorrent hardware.
I do get to see and play with a lot of interesting systems, but for most of them, I only get to go just under surface-level. It's a lot different seeing someone who's reverse engineered every aspect of an IBM PC110, or someone who's restored an entire old mainframe that was in storage for years... or the group of people who built an entire functional telephone exchange with equipment spread over 50 years (including a cell network, a billing system, etc.).
This is why I said "almost anyone." If I changed your words, I could disagree with you as well.
I greatly respect Jeff's work, but he's a professional YouTuber, so his projects will necessarily lean towards clickbait and riding trends (Jeff, I don't mean this as criticism!) He's been a great advocate for doing interesting things with RasPis, but "interesting" != "rational"