How APFS, the boot volume group, hashes, and Secure Boot all combine to guarantee the integrity of your system, and save you trouble and work.
reliability
Over 10 months, I’ve run over 100 notarisations on more than 30 apps. How reliable and responsive has Apple’s service been?
Scheduling background activities like making backups has moved from cron to launchd, and now to a more complex system. This has reduced the reliability of macOS and made it harder to support.
There is now a better way to estimate likely hard disk life than Mean Time Between Failures (MTBF).
Email needs to be turned into a robust service, with accountability and standards. How about it, OFCOM?