Howard2k
macrumors 604
Another alternative is to get a network-attached storage (NAS) device. Most will support Time Machine out of the box. I've used a Western Digital My Cloud EX2 Ultra without trouble for a few years as a Time Capsule replacement.
The main caveat, and it is a big one, is that most of the routers and NAS devices I mentioned currently support only the older variety of Time Machine over the Apple Filing Protocol. As a result, they will not work with macOS 27 unless they receive software updates from their manufacturers to use the newer SMB3 method. You also can't set them up for new Time Machine backups from macOS 26 Tahoe, but they generally work fine with older versions of macOS.
This is what I do too - SMB3 to NAS.
I do a Time Machine backup to local HDD every week or two, and Time Machine to NAS every hour automatically for convenience.
Nothing is perfect. I've had external HDDs fail, and I've had my NAS Time Machine volume crap itself on occasion and require a rebuild, but with the two volumes it's a very robust strategy.
I had an HDD failure in an iMac a decade or so ago, perhaps even longer, and I was up and running again in minutes after getting the drive replaced.
I'd never be without Time Machine, or some other strong backup solution.