Connect a storage account you already have, and every site's backup can be sent there automatically - no separate backup service to sign up for.
Add a storage connection once - a name, a host and port, a username and password, and the folder or bucket to use - and it's tested before it's saved, so you know it actually works before a backup ever depends on it.
Every hosting package already defines a backup schedule and how many manual backups a client can keep. Point a plan at a connected storage target and its backups start landing there automatically, alongside whatever's already stored on the server itself.
A storage password is encrypted the moment it's saved, and only ever decrypted briefly to test the connection - never stored or shown in plain text again.
Not every client needs the same backup destination. Point a premium plan at a dedicated storage target, and leave a smaller plan on whatever the server itself already handles - it's a setting on the plan, not a blanket rule for everyone.
A backup that only ever lives on the same machine as the site isn't much of a safety net. Sending it somewhere else entirely means a problem with the server doesn't put the backup at risk along with it.
A host isn't limited to a single storage connection. Set up more than one - a primary you use day to day, and a secondary you keep in reserve.