Victory points being visible in basic game
In a basic game, opponents' victory points are not supposed to be visible as development cards are secret even though the number of these ones is not.
In the UI, you can see how many victory point cards any player has on the icon below the longest road icon of each player. The displayed total number of victory points is correct.
It is the number of development cards not only VP cards. And knowing how many development cards a player has in total is public knowledge.