For people who weren't there, I think it's difficult to appreciate the kind of efficiencies which were gained by QNX and BeOS.
I first started running BeOS on my PowerPC Mac clone, back when those were a thing. There was a 1.44MB floppy disk circulating which contained pretty much the full OS, along with a web browser and various utilitied and demo applications.
Inside 1.44MB. It was phenomenal.
Compared to MacOS on the same machine, raw computational benchmarks were about 40% faster, and perceptually, the gains were even better than that, with essentially zero UI lag.
So, starting from scratch can have a lot of benefits, and you don't even need to throw out that much legacy.
Yea, I was quad-booting Linux, Win2k, QNX, and BeOS in 2000-2001. The most impressive thing about both BeOS and QNX were their responsiveness. BeOS was used for editing multiple video streams whereas the same hardware running Mac OS really struggled to edit a single stream at full data rates.
My ethernet driver for BeOS was terrible. If I left BeOS running overnight, most of the time I'd awake to a little popup saying something to the effect of "The ethernet driver for your 3c509 has crashed. Click OK to restart the driver." Thank goodness for userspace drivers.
I'm a bit surprised that the iso9660 and UDF drivers are still in kernelspace on Linux, since I can't think of a modern use case where performance of CD/DVD is relevant. Around 2004, I had a corrupted CD-R backup that would kernel panic OSX, Linux, and Win2k3 x64. Unfortunately, there was sensitive financial data, so I wasn't about to submit the image as a repro.
I first started running BeOS on my PowerPC Mac clone, back when those were a thing. There was a 1.44MB floppy disk circulating which contained pretty much the full OS, along with a web browser and various utilitied and demo applications.
Inside 1.44MB. It was phenomenal.
Compared to MacOS on the same machine, raw computational benchmarks were about 40% faster, and perceptually, the gains were even better than that, with essentially zero UI lag.
So, starting from scratch can have a lot of benefits, and you don't even need to throw out that much legacy.