> You actually can boot straight from USB as of very recently.
IITC that is still not officially supported (as a beta-test feature?), though many report it works as intended.
In the meantime if people don't want to use a beta feature the boot-from-SD-mount-root-elsewhere option works well too. You could also run it of an NFS share instead of a USB stick, though the performance metrics will differ.
Something you've always been able to do is to keep just the boot partition on a small SD card and the root on whatever USB device you like. And yes, even with the supposedly best-performing SD cards, they easily become a problem both with performance and failure.