Datastore backup

Is it good that we make backup datastore, is it gonna affect much performance?

Datastore2 (a special community module) will handle your data much more carefully than normal Datastores, so I recommend you use their module over the traditional Datastore, let alone two Datastores.

Backing up datastores only effects performance depending on how it is handled. Even if you could do it optimally, it’s usually better to just use Datastore2.