In my experience, Time Machine is rock solid. I've backed up and restored many times onto new machines and the only thing that it doesn't handle well is Homebre

In my experience, Time Machine is rock solid. I've backed up and restored many times onto new machines and the only thing that it doesn't handle well is Homebrew (or anything in /usr/local). I've had the same macOS installation for about ten years now. Also, in my experience, Crashplan is a steaming pile of garbage. Are you verifying that your restores are checksum-accurate? Are you verifying that all files are present after a restore? Neither was true for me, and support were unable to help.