I dislike the idea of backing up my data on other people's computers and disk drives. And paying for all that internet bandwidth is another negative. So I have

I dislike the idea of backing up my data on other people's computers and disk drives. And paying for all that internet bandwidth is another negative. So I have several USB3 external hard drives which I backup to in rotation, more or less the same sequence as we used to do with LTO tapes. On Apple Macs I use TimeMachine and on the Linux servers some custom scripts which basically achieve the same result. Of course, the backup scripts exclude temporary and other non-essential files. The other key factor is to monitor drive errors and being aware of the MTBF of disk drives and replace them before they become unreliable.