You’ve made a great start. How much further you go depends on your needs and threat model.

Rsync is ok as a start but there are dedicated backup tools that will give you access to your files at any point in time. This is important if you delete a file and later need it back after an rsync has already run and deleted it remotely too.

Rsync will not encrypt your backups. If a burglar takes your Pi will they have easy access to all your files too?

With rsync+ssh you are also vulnerable to either yourself (more likely) or a rogue process on your own machine deleting the files over ssh (e.g. ransomware attack).

The answer to that is append-only backups. A backup tool like restic has a backend you can host that does exactly this:

The –append-only mode allows creation of new backups but prevents deletion and modification of existing backups. This can be useful when backing up systems that have a potential of being hacked.

https://github.com/restic/rest-server

Take a look at restic to see what else you gain from switching to a dedicated tool versus rsync:

https://github.com/restic/restic#design-principles

There are others too such as borg.