There are other episodes like "One" in other iterations of Star Trek, so you might as well view this one for comparison.
Seven's last episode of the season finds her trying to cope with being the only member of the crew still conscious during transport through a particularly tricky area of space. It's not really that probing of Seven's character, or the fact that she used to exist in a Collective where she was never alone (that's mere implication). Mostly it's just an excuse to see how she reacts.
franchise * series * essential * character
Memory Alpha summary.