I have gotten in the habit (reminded by my Thunderbird calendar) of copying my critical partitions to an external device with Gparted.
Once you do it a few times it becomes just another mindless task.
15 minutes about once a week.
My key is keeping All partitions down to a manageable size… typically 15GB for / and maybe as big as 35GB for /home. (don’t forget to include the relevant swap partition!)
Other data on the other partitions is covered with normal backups… no need to copy those partitions.