People are talking this down but being impossibly hard to spot in darkness is kind of defining for gloomstalkers and whether people "need more" or not is entirely besides the point.
You wouldn't stop sorcerer spell progression at level 3 just because nobody needs more than fireball, would you? Same with gloomstalkers. They *own* the night. Well, used to own the night. Without umbal sight they're just regular rangers with a stronger alpha strike but really not much more ability to be a menace in the dark. They're no more stealthy than your garden variety druid with pass without trace.