In general, allowing essentially 4 attacks per round as a thief makes them kind of OP. Play a STR based rogue and for level 4 take the 2 weapon feat giving 1 AC and removing the Light requirement. So you have four d8 attacks. Main, Off, two bonus. Also, make sure your best weapon is in your off hand. Add fire for another 4d4. Add possible sneak of 2d6. Add weapon bonuses. Add +3 for strength, etc. It's the highest damage in the game.
I will check later but I do not think that´s how it works. You only get one attack with the main hand (plus sneak) and a bonus attack with the off-hand. Rogues do not have múltiple attacks.
Also currently dual wielder does not add the AC bonus.
A dual-wielder warlock with hex or a ranger with hunter´s mark will get similar damage output with because they add the +1d6 every time you hit the target, not once per turn like sneak attack, so you have an extra dice with the extra attacks like the ones you get with action surge or speed potion.
Plus they have spells
Plus you do not need to sneak or fulfil the conditions to sneak attack, you attack, you hit: you deal the extra damage every time.
That would change when rogues get more levels, of course. I do not say rogues are weak, I´d say they are far weaker than in the tabletop.
A level 4 Thief with the level 4 two Weapon fighting feat will do 3(1d8+Ability score + Proficiency bonus) Per round,
Any class does that damage with the same weapon and same ability score, not only rogues.
