Nextcloud AIO incremental daily backup take ˜90 minutes. Is this normal?

I have been using Nextcloud AIO mostly without any issues. One thing that I am not sure about is time taken for incremental daily backups on my system.
I have around 500GB of data and I use in built Borg backup to back up data to my NAS. Most of the data are pictures, videos and then documents. There is very minimal changes to these files (addition / deletion) on a daily cadence.
In spite of that, daily backup is taking more than an hour. Is this something expected?
Concern here is everyday for me nextcloud will be down for ~90 minutes.

Here is the link to original post with container logs https://help.nextcloud.com/t/nextcloud-aio-incremental-backup-takes-significant-time/206589

Can someone help me understand if this is normal or anything can be done to improve backup time?

Update: Borg backup performance takes big hit when backed up to NFS mount storage. When saved to local storage incremental backups take 5-10 minutes.