My install has been alive since 2014. I've never had the upgrade process outright break. One in a while it requires some manual intervention like holding something back, or ignoring some package while upgrading. The only really "big" problem was when i switched from Nvidia to AMD and had to boot from a usb to restore the video drivers after failing to completely configure them.

This install has moved 4 disks in this time. Never a reinstall, just an rsync a a new fstab.