The disappearance of a desk or a copier has small consequences, but if all data solutions disappear or are made inaccessible, the whole business stops. Not even the home office is pristine.
Encrypted backup stored outside your own premises is the only insurance against loss of important data.
The answer is simple, get yourself a backup hosting outside your own network, and preferably outside your own house. Backup encrypted in Weeam or other software is moved with (SFTP) by a script (no software required) running on a standalone computer. Weeam or other software may trigger this script from Weeam, but the safest thing is probably that this goes completely independently on schedule. This machine (with backup script) is silent if everything goes well, but notifies by email if the backup fails.
Make sure that all other services are blocked on these backup volumes, and that only the authorized IP address has access to the owner’s volume on the backup host.