"Dull to play" is not the opposite of "efficient", and vice versa. Power is not the issue here.
Melee rogues have no progression other than "up-to-date dagger(s)" and tend to become invisible warriors and/or invisible spellcasters, with the occasional sneak attack. I had tried to create a rogue-ish character on the previous alpha build when the preset was introduced and never succeeded in doing so. Melee rogues can't exist as of now, they will inevitably become invisible warriors and/or mages due to lack of dagger/rapier oriented skills or melee way of the ranger skills.
Honestly, right now, if I had to try another build around sneak attack, I'd probably go either full ranger, get a crossbow as fast as possible and just range sneak attack, or go for a 2 handed strength based melee build with flurry, in both cases picking the invisibility spell at creation and never bothering equiping daggers.
Rogue archetypes have no real game mechanic associated with the concept as of now aside from sneak, pickpocket and lockpick, which makes the rogue type just a name on a starting preset.
If melee rogues are to exist, they will need a Way of the Thief/Assassin/Sneaky Slippery Backstabber ability (you name it), and dagger/dexterity/rapier exclusive skills. As long as they don't, they're stuck to being warriors with a dagger. It is always possible to make sneak attacks only available to daggers but that wouldn't solve anything really.
