First off, dependencies aren't just other services. You can have "when the network interfaces are up" as a dependency, for example, so this isn't just about how

First off, dependencies aren't just other services. You can have "when the network interfaces are up" as a dependency, for example, so this isn't just about how many programs run at once and in what order. Second, you care about it in scenarios where predictability is required. If your customer says they want their smart TV or their POS or whatever to boot in no more than X seconds under normal operating conditions, it's really not cool if the system can take a slightly different way to multi-user.target. Dependencies across separate chains can contend for resources, for example. "But these are embedded systems, you should just run rc.local" I hear you say? Right. These things run like fourty services, from telemetry to user interface and from firmware update to encrypted cloud backup, half of them written in Node.js, on top of a system that's basically built for systemd. It's not something you can extricate yourself out of. I don't know if there are equivalent examples in the server world (not my field), but I wouldn't be surprised if there were.