I actually use this as a cheap data backup mechanism. I have a primary database cluster on SSD, and two replicas on two separate harddrives. All running as three postgresql clusters on the same machine.
The harddrives run intentionally on different filesystems, so that filesystem bug will not eat all my DB data. (in case someone wants to suggest raid ;))
Anyway, I don't fear the lightnings/storms/power surges where I am as much as I do the inevitable failures of the storage devices, or kernel bugs.
This is just a part of layered protection I have. Offline backups are nice, and I have them too, but they are out of sync all the time by definition. So unless absolutely needed, having a real-time synchronized replica is much more prefered.
But it's not really complicated. Making a replica is just a few shell commands and two new systemd service files. It's probably simpler than setting up wal-e, especially if you count in the setup and maintenance costs of those cloud accounts, and the need to keep up with regular payments for the services, and recovery not being as simple as switching to an already configured and uptodate replica is.