Thief still gets another bonus action and still maintains having the best mobility out of all the classes and options. Being undervalued doesn't necessarily mean it's a bad thing either, it's dependent on context. And yes, it completely alters the action economy and balances it with a bias towards something else. But that something else is most likely not intrinsically bad either. So shrug.
Theifs extra bonus action makes it one of the best classes in the game right now, while arcane trickster is left in the dirt. This is mainly due to being able to offhand attack twice even if you didn't make a mainhand attack with a light weapon first. Hopefully this is a bug. But even if that does get fixed, the extra bonus action is still very strong.. perhaps still busted right now, it's hard to say.. but certainly once multiclassing is in, it will again be the most broken subclass feature.There is no way that that subclass feature can stay in the game the way it is.. it needs to be either severely restricted, or removed, and because of that we can't really say rogue is okay just because of this feature.