As long as you stick to what's in Synology's package manager it's pretty end-user friendly. Though that only covers the normal file/photo/video/contact/calendar/backup management stuff. To set up a pihole you'd have to configure the docker image or run a VM, which is probably beyond the standard user's repertoire.
For friends and family unraid is nice because it has a much bigger repertoire of "Apps" (mostly docker containers with some minimal UI integration). It demands a lot more from the user than Synology and looks a lot scarier, but there are no difficulty spikes. Once somebody knows how to use it it's pretty smooth sailing without having to learn anything new.
That's fair, Synology can be confusing, and it's permission system is frustrating. However, my experience has been that many people use Synology, and I have found detailed articles about everything I've ever wanted to do with it, including adding unsupported 5GbE USB ethernet adapters. It's docker support is nice and makes it easy to setup and run infrastructure like MySQL, postgres, redis, iperf3, and apps like nextcloud, firefly III, only office, etc. It manages certs per-domain (import existing or have it use lets encrypt), and the reverse proxy handles multiple domains and sub domains and makes it easy to remotely access individual apps (or hosts and ports) by redirecting port 80 to 443 and then 443 to whatever the particular docker port is (or IP address and port of something else on your LAN). I also like that the apps can run on my SSD-only RAID storage, and then I have a separate large RAID on spinning disks for NAS storage. Then the Synology devices, fiber ONT, router, main switches are plugged into my UPS backup. For personal stuff I like the Synology platform because it's hassle free, and I think the tutorials by random users makes it approachable to consumers.
For friends and family unraid is nice because it has a much bigger repertoire of "Apps" (mostly docker containers with some minimal UI integration). It demands a lot more from the user than Synology and looks a lot scarier, but there are no difficulty spikes. Once somebody knows how to use it it's pretty smooth sailing without having to learn anything new.