UGreen or Synology???

[billykris2528]

Hi, I would like to ask your recommendation in buying NAS.
I’m completely new with NAS storage system and doesn’t have any experience in IT fields, so I can say I’m completely blind with all these things  

I currently use Google Drive & Youtube to store my work-related files. 
Now I’m considering to buy UGreen DXP4800 Plus or Synology DS925+

Primarily, I would like to use NAS to:
1. Store my work related things so I can access it anywhere across different devices
2. Allow my team to access work related files anywhere through a shared link (without the need to create account for them), just like a simple link sharing in google drive.
3. Backing up photos & videos from my iphone so I can have more capacity in my phone.
4. Storing & securing my client’s personal data from breach, but I still can access them when I need to.
5. Using Plex/Jellyfin application to store training videos & allowing my team to access it like netflix (but with training video) anywhere & anytime by sharing link (like youtube) -> is it possible?

Please give me insight on those two 4-bay NAS.
And is it possible for a NAS to handle those 5 things?

Thanks in advance.