Synology > Nextcloud on VPS(I assume what cloud machine is that you are talking about) imo. Nextcloud is quite resource intensive. You won't be happy with just $10/m VPS, that is aside from obvious storage size problem.

Synology is expensive but reliable. Does one job well but somewhat limited. Synology and Nextcloud have different values and strong points. You'll be happy if all you do is just file sharing with both options, synology being easier of course.

I use my own machine at home to run Nextcloud among other various selfhost stuff. It works flawlessly. After the initial setup, almost no tinkering is necessary. I just reverse proxy Nextcloud so there's no issue with accessing but if you can't/don't want to, you can use something like Zerotier or Tailscale. Personally recently migrated to Tailscale as it's just more user friendly.