As someone who doesn't really care much about D&D and likes other ttrpgs far better for varying reasons, I still think you're wrong about the cooldown issue and also about how obscure D&D is. If you ask any person who doesn't play ttrpgs about games they've heard of, D&D will almost certainly be first on the list. I don't think it's the best system by a longshot, and if it changes I would probably be in favour of it purely because there are aspects of it I think really need changing (though rests aren't high on that list for me). But I think you're being hyperbolic and dismissive about the game in a way that's not really fair.
Regarding Baldurs Gate in particular, I think trying to change things as much as you're suggesting isn't feasible because it would probably require tearing a whole lot down and starting from scratch. That is something I can't imagine them being willing to do that at this stage and frankly I doubt that it would be viable at this stage. They may be at a stage where they can tinker with the rest system, but completely replacing it would require going back and reworking a whole host of systems from the ground up, altering everything about the way spellcaster classes play. Then going back to every other class and making sure they're still interesting and fun and worth playing compared to casters. And even then you need to look at casters more as well, making sure that a Warlock still has something to offer compared to a Wizard. If they were thinking about implementing multi-classing, that'll need to be accounted for as well. All of that stuff is perfectly doable, but it would require massive changes to the D&D system that you don't want to be doing at this stage in the games development.
I don't know if your suggestions would actually be objectively better (I've played Solasta and found the rest system and combat in that game far more smooth and enjoyable, same with Pathfinder: Kingmaker which used a rest system as well so I do think a degree of this is simply how Larian chose to implement their system) but I don't think it can be implemented regardless. Plus I do think there's something to be said for the fact Larian has been claiming this to be ass close to the real tabletop experience as they can make it. If they had just said they're adapting the 5E system it'd be simpler but they've made a promise to customers, and deviating as far as your suggestion would be breaking that promise and there'd probably be repurcusions. And it's unreasonable to expect people who came because they were promised a thing not to get mad when the people who made that promise actively choose to go against it. Larian made the promise and got themselves into the situation. Now it's on them to deal with it.
