C. Let me rephrase. A game would have to consider every possible reaction and prompt you to act. With a DM you would simply interrupt him and start a discussion. A massive difference in my opinion.
Given the absence of DM we are feeling the limitation of the video game environment here.
Except, as Already Established With Incontrovertible, Tangible Proof, it is indeed quite possible and very straight forward to put a reaction system in the game that works with all viable reactions as defined by the ruleset we're using. It's been done. It works. Reactions are specific things, with specific rules and specific triggers - they aren't fluffy 'hash it out with your dm' things - they're a literal, mechanically described part of the system. They only come up in specific situations, and only when their individual triggers are met. They can only happen once per round for each player. Watch any D&D stream you like - is the combat bogged down by a constant stream of player reactions? No, it's not... and it isn't in a video game format either, as others have posted very credible video proof of.
Having an opinion is fine, but when that opinion runs contra to established and demonstrated evidence, it is not an argument - it's just stubbornness.
Edit for the above post:
I don't recall to clearly about the text, but it never seemed like a lot to me, personally. I recall counterspell just being "Enemy Mage is casting a spell (Blight), would you like to cast Counterspell?" I may be mistaken though, my recollection isn't clear. Either way - yes, the text in the prompts should be short, to the point and clear, regardless of anything else.
I absolutely agree that you should be able to assess the battlefield before making your choice, including spinning the map about to see what else you might have to consider, yes. I've never had a problem with that in Solasta, because generally the map zoom and positioning is good enough to let me see everything I need to, but in the odd case it doesn't, that would be much desired. BG3 is terrible at letting you see what you need to in general, so it must let you move the view around while deciding.
I think the grouped reaction only giving you one, that you're experiencing, is a bug, or else you're misreading the screen. In Solasta, if an enemy leaves the controlled space of three of your party members, they can each react, and all three can choose to use their reactions, some of them can, or none of them can. You absolutely have control of who swings and who doesn't and you're not limited to picking just one.
Agreed on the last point -they've had a few other little bugs here and there to work out - in the early stages reactions refreshed at the top of the round, not by character turn, and that caused issues. They've since fixed that one though.