I use free instance of NextCloud offered at its official website (which of course, I don't administer). Now, at this point I believe - unless the NextCloud instance is under my administration, it's not secure and 100% private. And to some extent (or maybe to the fullest) it's worst than even google in terms of security and privacy. Because the person who is behind the free nextcloud instance can easily access everything I've stored.
So my question is -
1) Is it correct? (my assumption above)
2) I won't go premium at this point. So, what's the best free alternative? Or should I stick with Google or Dropbox than other free providers?
Thanks in advance.