Yeah, you should be scrubbing weekly or monthly, depending on how often you are using the data. Scrub basically touches each file and checks the checksums and fixes any errors it finds proactively. Basically preventative maintenance. https://manpages.ubuntu.com/manpages/jammy/man8/zpool-scrub.8.html
Set that up in a cron job and check zpool status periodically.
No dedup is good. LZ4 compression is good. RAM to disk ratio is generous.
Check your disk's sector size and vdev ashift. On modern multi-TB HDDs you generally have a block size of 4k and want ashift=12. This being set improperly can lead to massive write amplification which will hurt throughput. https://www.high-availability.com/docs/ZFS-Tuning-Guide/
How about snapshots? Do you have a bunch of old ones? I highly recommend setting up a snapshot manager to prune snapshots to just a working set (monthly keep 1-2, weekly keep 4, daily keep 6 etc) https://github.com/jimsalterjrs/sanoid
And to parrot another insightful comment, I also recommend checking the disk health with SMART tests. In ZFS as a drive begins to fail the pool will get much slower as it constantly repairs the errors.