A rogue is so much more than a lock picker and a trap finder even though he should be doing those things as well because if he or she is a good rogue they would be out front sneaking around and scouting the area, planning ambushes and devising battlefield tactics. Every PC in the current build of the game that is not a rogue can sneak and hide, but they do it badly. Your party should never be surprised in combat if you can absolutely help it because of the disadvantage on dice rolls and a rogue played well will not only fill this role for you,
I think that role, certainly above-ground, is what the ranger class is supposed to do. The ranger is, after all, essentially a scout. Underground, the ranger can still continue to be the scout, especially with the right choice of favoured terrain. I don't see any advantage that the rogue gets in this any more.
but while the enemy is advancing on your party and focusing all of its efforts to kill Cale, your crafty rogue will be doing what he does best, killing them all from the shadows.
Killing, whether from the shadows or not, is not great behaviour for a scout. The best reconnaissance is the reconnaissance that leaves your enemies none the wiser that someone is interested in them. The easiest enemy to dispatch is the enemy that doesn't know they are in danger. Recent editions have certainly made the sneak attack (formerly the backstab) easier to implement, but it was quite hard to position for in the earlier games, and only used a limited range of weapons. I think the relaxing of those restrictions is an acknowledgement that most players see the rogue primarily as a damage-dealer and want more opportunities to Sneak Attack.
That is what the new-look rogue seems to be built around. They are now much more assassin than burglar, with the Sneak Attack being their dominant feature. PnP rogues have the Expertise feature which emphasises the skill monkey part of their role, but none of those skills is exclusive to the class. They have become highly-skilled generalists with murderous damage-dealing instead of their old primary role of scouts and trap and lock-defeaters.
