I am happy with my Synology, it meets my needs.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
I run an Intel 10th gen desktop motherboard in a large case. Win11 unregistered copy works fine, even better on Windows Server.
It has tons of horsepower and enough expansion. Win 11 updates itself, reboots and I have auto login enabled so it lands back at the desktop.
It's been idiot-proof and very low maintenance.
Handles many 4K60 h265 10-bit transcodes.
There is only Synology and DIY.
I got myself 4bay QNAP, and then bought 4bay extension. Little did I know that the extension cant expand current pool, so I cant use 6+2, only (2+2)*2. (bullshit). The CPU is underpowered for basically anything, including its web-server (sometimes it just doesn't respond at all), its constantly throwing "please upgrade firmware" stuff (why cant it update on its own?), its "apps" are a joke, I have a "admin" account I cant disable or rename, I have a "guest" account I cant disable or rename (only set its privileges to 0), there was a time where its VPN login page had exploit where you could get NAS Root access trough that VPN login page without knowing username or password (was similar to sql injection), and overall I regret the decision going qnap to save few bucks ever since.
I have no idea how synology is, but since I got burned so bad my next version will be custom build NAS running something like freenas or similar.
synology 423+
does transcoding
synology automated backup of any/all computers on the network
synology drive works like dropbox
set and forget offsite backup with hyperbackup
can run docker containers and plex
I highly recommend UNRAID. I was in your same situation a month ago and now have a unraid instance running everything your mentioning with mix matched drives and parity with unlimited expansion potential.