Selfhosted

Hello, not sure how on-topic is this, but I'll ask anyway. Since I'm wrapping my head around this topic for long time to no avail.

I'm planning to buy NAS mostly to store my music, pictures and documents on my place. At the beginning I'd like to keep it simple so I don't plan to install billion things on it. I would definitely want to install adblocker like PiHole/AdGuard. I'm also eye-ing Tailscale for remote access (no public IP) and Jellyfin/Emby for music streaming at home. So apart from usual NFS/SMB file shares, let's say there are these three apps I'd like it to run at the beginning.

The NAS has to be as quiet as possible, so even thought it's more expensive, I'll have to go with SSD drives. Looking at prices two 2 TB (in mirror RAID) should be doable and should be enough space for me, at least for now. I'm no hoarder.

I have few other "must-haves":

1. decently working companion app that automatically backups pictures from at least 2 android phones (my wife needs to deal with it and she's not really friends with tech stuff)
2. possibility to upgrade storage other than just replacing drives for bigger ones
3. simple, easy to use (both setup and "rescue") scheduled backups to external USB drive
4. I knew I had something else but it completely slipped out of my head

That brings me to what's available. I almost pulled the trigger on Synology DS423+. It looks reasonable powerful, I can put 4 SATA SSDs and 2 M.2... that's what I thought. But it turned out it's not possible to use M.2 as storage with anything but Synology's own overpriced drives that aren't even available in my country. So, it's just four SATA drives, which is... "not great, not terrible" as some would say. What seems to be a big plus is the DSM. Everyone I know really praises it. Plus it seems to have very good reputation in terms of longevity of devices.

Then there is QNAP. Apparently their system QTS is not as polished as DSM, but everything needed should still be there. There's similarly priced, similarly equipped TS-462. It's just dual-core CPU, but has more RAM (not upgradeable though) and it seems it can accept M.2 as storage at least. As per internet research, the build quality is just as good as Synology.

And then there's Asustor, which I heard about years ago and then completely forgot they exist. Last week my friend mentioned this name, so I checked their offering too. Well, Nimbustor AS5402T looks absolutely the best on paper! Well, it only has two regular drives, because it's got FOUR M.2 slots! I assume it's because SATA is on decline, but M.2 SSDs are cheaper than SATA nowadays so it's actually better for me to have the numbers reversed. And it's cheapest on top of it. So where's the catch? I presume the ADM system is piece of shit. Right? Or is it build quality that's bad? Reliability? IDK.

Which of these three do you think would be the best for my needs? I'm more than open to other offerings and suggestions too! Thank you very much!