I did something similar years ago. Couple of drives in an old beige tower case. Setup the sharing wand what not. Not exactly 'hard' but it was one thing. Time consuming. Once you have done it a few times the novelty wears off and its more of a chore to mess around with the thing. NAS boxes like that 'just work'. You plug some drives in, set it up, done. However, one comment in here puts it perfectly. The software on syno is wildly out of date. It has been for 15 years. Ease of use is now outweighed by something recent software wise. The syno guys are literally leaving nearm 20-30% perf uplift out. For 'reasons'. Those reasons are wearing very thin. It will mean I need a different backup solution for my computers. One that handles full disk incremental and stored windows and linux on the remote drive and not something I 'run once and awhile' and perferably open source.

20 years ago it was a chore but nowadays it's faster than baking a cake. 10 minutes prep time (configure os and add drives), 10 minutes bake time (installation) (or 10+ hours bake time if count building the array)

But let's assume you don't have a clue and have to follow some tutorial and do some reading and it takes you 2 hours. That's amortised across a decade. Especially now when easy distro upgrades are basically unattended so you can use the same setup for a decade and stay up to date.