You asume that hardware raid is always superiour to software raid regarding data integrity. This was right 15 years ago or when you look at software raid based on "old" filesystems like ext4/ntfs or in general at filesystems without "CopyOnWrite" and checksums on data and metadate.
Modern softwareraid especially based on ZFS is by far superiour in nearly all aspects ex performance, features, data protection, crash behaviour or portability ex
Write hole problem
A hardware raid adapter updates disk by disk on writes (ex a mirror). A crash between can result in a state where data state is different on both disks. As there are no data checksums you cannot detect which data or part of the mirror is valid and which is not. A BBU protection can reduce the problem but cannot avoid. ZFS can avoid problems due CopyonWrite and detect problems based on checksums on all datablocks on any disk in a raid,
"Write hole" phenomenon in RAID5, RAID6, RAID1, and other arrays.
Silent data errors (random data corruption over time)
Without data and metadata checksums there is no chance to detect these problems based on a hardware raid controller. ZFS and software raid detects all corruptions and can repair on the fly
Secure sync write
A hardware raid controller can do with a cache and bbu protection but without verification. ZFS can protect its rambased writecache with an Slog and checksum protection. As ramcache is mainboard ram this is faster and bigger on ZFS.
Portability
For hardware raid, you need a compatible controller on a failure. With software raid you can just connect the disks to any controller and import the datapool.
Expandability
With ZFS and software raid, you can scale storage to hundreds of disks and Petabytes of storage and very high data rates. A modern mainboard cpu scales much better and is much faster than a hardware raid cpu. Software raid with offers fast rambased readcaches in the area of hundreds of gigabyte ram. Softwareraid can be build from or extended by NVMe disks ex caches, special vdevs or Slogs. Hardware raid is limited and was faster only a long time ago.
Above of these controller based items, ZFS offers superiour rambased read/write caches, additional SSD/NVMe readcaches with read ahead, special vdevs as a superiour tiering alternative to improve access to metadata, dedup tables or small io, superiour compress, dedup and encryption options - can be set per filesystem, sync of multi petabyte storage systems in near realtime under heavy load based on snaps. ZFS snaps can be created without delay and initial space consumption. Even 10000 snaps are no problem regarding performance and stability. Snaps are read only and offer a perfect protection against ransomware.
ZFS and software raid can give you all the superiour goodies, hardware raid cannot (even a combination of ZFS and hardwareraid would be really bad as you would loose many features).
You may read some of my manuals like ZFS basics or principles at
napp-it.org - free ZFS NAS SAN Server with user editable web-gui // All In One server = virtualized ready to run ZFS-Server
napp-it.org
Most of the infos are valid for any ZFS system incl. Qnap or any ZFS system, others for native ZFS (Oracle Solaris) or the Solaris forks like OmniOS (a enterprise class storage OS),
OmniOS Community Edition that allows to use an average storage server ex SuperMicro, Dell or HP.