> SpaceX also has a simplification streak: the Raptor engines being the canonical example.

Not necessarily. Your engine which used to have 200 sensors perhaps now only has 8. But you now don't know when temperatures were close to melting point in a specific part of the engine. When something goes wrong, you are less likely to identify the precise cause because you have less data.

Many of those sensors are not to enable the rocket to fly at all, but merely for later data analysis to know if anything was close to failure.

In yesterdays launch, if the engines had more sensors musk probably wouldn't have said "an oxygen/fuel leak", but would have been able to say "Engine #7 had an oxygen leak at the inlet pipe, as shown by the loud whistling noise detected by engine #7's microphone array"

My #1 rule for all engineering: simplicity is harder than complexity.

I truly wish more software engineers thought this way. I see a lot of mentality in software where people are even impressed by complexity, like "wow what a complex system!" like it's a good thing. It's not. It's a sign that no effort has been put into understanding the problem domain conceptually, or that no discipline has been followed around reducing the number of systems or restraint over adding new ones.

I've seen incredibly good software engineers join teams and have net negative lines of code contributed for some time.

If we ever encountered, say, an alien race millions of years ahead of us on this kind of technology curve, I think one of the things that would strike us would be the simplicity of their technology. It would be like everything is a direct response and fit to the laws of physics with nothing extraneous. Their software -- assuming they still use computers as we understand them -- would be functional bliss that directly represented the problem domain, with every state a pure function of previous state.

We might get to this kind of software eventually. This is still a young field. Simplicity, being harder than complexity, often takes time and iteration to achieve. Often there's a complexity bloat followed by a shake out, then repeat, over many cycles.