Most of the OP's discussion on mechanics are solid criticisms of the current game, but I'd just like to drop in to suggest to them that they take a look at Solasta's implementation of combat. There might be a lot else lacking in that game, but they do demonstrate how completely possible it is to implement 5e rules into a video game almost entirely faithfully and have them create sooth, intuitive, engaging and thoroughly satisfying combat. Reactions are handled exactly as your DM will handle them with a player at the table - they game briefly pauses to ask if you'd like to use the reaction whose trigger is being met, you say yes or no, and then the game continues... it's smooth and very unobtrusive, and does the job very effectively.
Meanwhile here, we have a game claiming to be Dungeons and Dragons, which doesn't even *have* the shield spell in the game right now.
