I haven't tried it, but it's a thought provoking question. Like, Extra Attack is only worth so much in a vacuum, it has to synergize with other portions of the class kit to really be "worth it". There's a reason they can throw it in to various gish subclasses (like Swords bard or Bladesinger wizard) and it doesn't obviously become broken. Whereas, I think if those subclasses had gotten Sneak Attack progression as a rogue instead, people would have had major issues with them.
I do think if you're going to trade in Extra Attack for something, you really need to throw out Fighting Style as well. If I made Paladin a full caster, I'd probably dial back some of the lower level features and spread them across Tier 1 and into Tier 2.
If I replaced Ranger Extra Attack with Sneak Attack, I'd definitely dump fighting style. I feel like something else should be dumped, but I'm not sure what. Maybe the 11th level archetype feature?
Yeah I think you're right. I will say though, some amount of the classes power comes from adding damage buffs more than once a round, so I don't know if we would need to drop anything else.
Perhaps Ranger's Sneak Attack could progress somewhat more slowly, as well. I'd definitely also rethink my plans for an alternate Ranger in terms of adding things to the base class at low level, and instead just beef up Natural Explorer as planned. Perhaps with an ability to always use Sneak Attack against a favored enemy, regardless of circumstance?
I'd get rid of extra attack and spells. Which would basically just make him a rogue.
Sneak attack is the sole defining role of the modern rogue. Searching for and disabling traps, opening locks, sneaking, and all the other skills are open to every class. If you give sneak attack to any other class - why even have a rogue?
I disagree, but that also isn't the question.
The question is one of balance, not of class identity.
As for class identity, however, this wouldn't happen in a vacuum, and sneak attack would be replaced, rather than shared. IMO the Rogue is the Rogue with or without Sneak Attack, as long as they are a non-straightforward combatant with incredible skill expertise.
I'd like to see them get Extra Attack and maybe even add "make a single weapon attack" to Cunning Action, and give each attack a short list of negative effects they an impose on an enemy.
My thought originally was to then give SA to an Assassin class, but I'm exploring if it wouldn't be better suited to the Ranger instead, and stick with the semi-mystical Assassin I've been building.