[hnlmorg]

Any sufficiently complex software ecosystem eventually ends up amassing a heap of ugliness due to assumptions made at the time that are no longer correct nor are easy to change. Web development is a great example of this: the modern browser is not that far removed from an operating system and how many quirks do they need to cater for these days plus how many footguns do web developers need to consider?

Also some of your specific concerns are impossible to resolve. Take SIGNALS for example. They're ostensibly just callback functions / events. It's very easy to do event-driven programming if all of your events are being raised by the same language runtime as the code you're writing your application in, but how do you raise an event that crosses application boundaries and where your application code would be written in a different language to the event bus (the kernel in this instance)? You ultimately end up with some kind of IPC ugliness and the best solution in the 70s was SIGNAL. Given its now core to the OS, stripping out SIGNALs from Linux would be as easy as stripping HTML from websites.

There are plenty of radically different successors to Linux though. But they all have their own rough edges too. Ultimately these things are complicated and you always end up making compromises somewhere.