An expensive lesson learned in redundancy. It's a shame to see things play out this way, but sometimes a lesson is taught in a brutal fashion. I imagine the author will be more careful in the future regarding off-site backups, additional technical partners, contingency plans, etc.
There's a pretty hard cap on the level of redundancy you can do with a two-man company, as I assume a two-man company does not bring in a lot of money.
It won't be entirely up to date when the worst case happens, you'll be unavailable and you'll probably have lost a day of data or so, but you won't have lost everything.
Rclone to AWS or Google or whatever is easy to set up, add a daily dump of your database to the folder you back up. Unless you handle a lot of data, costs are probably not a big factor.