Scenario #1: You are a rogue who has ended up in the midst of combat with multiple foes. Before your turn comes, there will be 2 people attacking you. Let's say in this case, the first one is a Wizard that uses Fire Bolt cantrip on you and hits you, but rolls a 1 on damage. Next, a Path of the Berserker subclassed Half-Orc Barbarian runs up to you and crits you with his first attack with his Greataxe, getting Savage Attacks racial which increases his crit damage by another die roll, and potentially getting Brutal Critical class feature (if the enemy is 9th level or higher) for at least one more die roll of damage.
As a rogue, you have a class feature called Uncanny Dodge. This means you can (read: not must) use your reaction when an attacker you can see hits you with an attack to reduce that attack's damage against you by half. With a preemptive "set it and forget it" system where you use up your reaction the first time it is available to be used each round of combat, in this scenario you would use Uncanny Dodge on the 1 damage Fire Bolt cantrip, effectively wasting the ability. You could have used it to reduce the damage of the massive Barbarian Crit that is probably going to one-shot you to 0 HP.
No.
You don't know how much damage you take when you use uncanny dodge.
Uncanny Dodge p96 Player's Handbook
Starting at 5th level, when an attacker that you can see hits you with an attack, you can use your reaction to halve the attack's damage against you.
Rules as Written: Rogue chooses to use Uncanny Dodge when they get hit, but before the damage is rolled.
I never said you knew the damage you were going to take when you choose to use Uncanny Dodge. But, you don't have to know the precise damage numbers you are going to take to know that it might be less worth using it on a cantrip that does 1d10 damage with no damage modifier, or to know that it is more likely worth using it when a Half-Orc Frenzied Berserker Barbarian is swinging his Greataxe at you where he already gets modifiers to damage from strength and rage bonus on top of his 1d12 Greataxe damage. This doesn't even take into account the fact that, if he used Reckless Attacks, the likelihood of him critting is higher than the cantrip.
In my example, I was stating that the damage ends up playing out that way, not that the player knew the damage would play out that way in advance. In this case, the player would have used their knowledge that a Barbarian is probably going to hurt a lot and saw that that Barbarian was going to have a turn before them, so decided to save their reaction for that rather than use it on the cantrip, and that decision paid off.
Scenario #2: You are a Cleric that went down the War domain path so that you could wear heavy armor and use martial weapons and get into the thick of the fight. Because you plan on using either a 1h and shield or using a 2h weapon, you decide to take the War Caster feat. The War Caster feat allows you to do better at concentration checks to maintain spells, allows you to cast spells that require somatic components (a lot of spells do) while having both hands full with said shield or 2h weapon, and additionally allows you to use your reaction to replace an Attack of Opportunity with a spell that has a casting time of 1 action that targets only that creature. This is a very common feat to get on "battle caster" type builds.
We have no idea if this feat is even implemented in Baldur's Gate 3.
As such using it as an example of how it makes a completely different implementation of reactions necessary is silly.
There's nothing silly about the example at all. Larian has already confirmed feats are going to be included, and while they haven't said which ones will be included, it's not overly presumptuous to talk about any of the feats that exist in the PHB with the assumption they might be in the game. If I were talking about less-often-used feats in supplemental books, it would be more presumptuous, but the PHB is the standard game that Larian themselves have said they're mostly pulling from. And truly silly would be making up my own feats to make a point, but I definitely didn't do that either. I used the most basic version of the game and took a feat that is very commonly chosen as an example. Besides, it was merely one example. There are more feats which deal with the use of reactions, such as Defensive Duelist and Sentinel, which are also in the PHB and could have similar arguments about how much worse they get when the player doesn't have the agency to control their usage. These feats are taken for more than one reason and taken very often by players, so it is an important enough part of the game to foster discussion around worries, even if those worries are unfounded in the end.
Early access is 35 days away.
Speculating on imagined edge case scenarios from a build posted 40+ days ago does not seem to be very valuable feedback.
Those of us who are playing Early Access will provide plenty of feed back on the build that we get to play.
If you choose not to participate in Early Access I'm sure lots of videos will be posted that will show you how the feature plays out and you could provide more meaningful feedback then.
They are not imagined edge case scenarios. There will be feats, and these are vanilla PHB and extremely commonly used in 5e games.
Developers need feedback on the minds of the players at all stages in development, from the announcement of features, to the showcasing of features on a stream, to the early testing of features, to the late testing of features, and even after launch. There is no point in which feedback is not valuable, and to suggest that any feedback that is constructive criticism with reasoned examples is not valuable is to simply attempt to silence a narrative you disagree with. Healthy discussion is never a bad thing.
