The problem is sometimes you only find out your backup is corrupted when you need it.
But for anything above a few TB, running your own hardware will be way cheaper if you take say a 5y horizon. Disks are so large today that you don't need a big config. In fact you might even keep two copies to reduce the risk.
Of course there is the occasional trip to the datacentre. I made that mistake. I pay more in uber than I saved by picking a datacentre far away.