Japanese manufacturing addressed this too! There’s a whole branch of Deming’s work around supply chains and how it’s often worth working with “more expensive” suppliers when their quality is consistently high, because compensating for low quality inputs to your own work is far more expensive.
(Tailscale founder here) Two main differences: first, every DERP server used by your tailnet must be accessible by every node on your tailnet at all times, otherwise you get hard-to-debug netsplits. That's a very high bar to maintain so we've historically recommended you don't try. In contrast, peer relays are "if a given pair of nodes can connect through any of the relays, go for it" so deploying one is always a performance and reliability improvement.
Secondly, peer relays support UDP while DERP is TCP-only. That would be fixable by simply improving the DERP protocol, but as we explored that option, we decided to implement the Peer Relay layer instead as a more complete solution.
[Tailscale CEO here] I see a lot of comments asking why Tailscale would branch away from our "core product" and build this thing that seems unrelated at first. One answer is that just about every single Tailscale customer (or homelab user!) is dipping their toes into AI right now, and they often come to us and ask how to integrate their stuff into Tailscale. Aperture is our answer to that.
A separate goal I have personally: demonstrate that anyone can build really neat stuff directly on top of the "Tailscale platform." One of my rules for the Aperture team was, you're not allowed to change core Tailscale, you have to build entirely on top as if you were some partner company. So this is a demo of how anybody can make pretty slick, easy-to-use, and yet highly secure stuff by building on Tailscale (the open source packages, or the commercial product, or both).
(I'm a Tailscale employee) The recent versions of the Tailscale k8s operator actually used a pre-release of the Services feature to do exactly that. So, not much difference. The official Services release is making that functionality available for more use cases (and generally better documented and user friendly).