TL;DR: Yeah, you can object to the amateur vs professional argument all you want, but that's basically what's happening. It's like wondering why people prefer Broadway produced-plays more than an elementary school play. But yeah, Critical Role saved my group.
#
I was in basically the same position a few months ago. I just didn't understand why anyone would watch someone else play a game you could play. Everyone in my D&D group watched / listened to Critical Role and said I'd love it, but I just couldn't. The same applies to video games. Just don't get why you would watch someone play WoW when you could just load up the game and play yourself...outside of world first raid kills or boss tutorials...or beta access videos. But as a thing to do for entertainment, nope.
Then the CR crew put out their Call of Cthulhu one-shot. I waited for that because I wanted to see what they would do with a game closer to my heart. I love me some D&D, it got me into the hobby, but it's so much just a repetitious rehash game after game, module after module. Find a fight, easily win, kill the monsters, loot their bodies, rest up as an after thought...lather, rinse, repeat. It was boring. Something that's supposed to be fantastic had become mundane...
So CR does Call of Cthulhu. It was great. The adventure was interesting, the Keeper was great (even if he flubbed a few rules), the players were great (even if some of them clearly had never looked at any rules for the game before sitting down at the table). It was kind of an event. Like what a group of theater kids with time and money would do. The costumes were great. The sets were incredibly well designed. The props were fantastic. If ever there was a produced version of a RPG session, that's exactly what you'd want it to be. Everything you'd want it to be. It was like watching well-produced improv theater with a game system. It was amazing. (They're doing much the same thing with Deadlands currently, but that's beside the point.)
So I decided to give the proper Critical Role a shot. It was nowhere near as well produced, the players showed up in their street clothes. The set was a generic tavern with some lights. They spent a few minutes talking about their cool new table...then launched into about 20 minutes of announcements and ads...after about 5 minutes of that I was ready to turn it off. I tuned it out instead. Letting it play in the background as I did something else. Then they started playing...
I know you're dismissive of the amateurs vs professionals argument. But it's true. It's the difference between watching an elementary school play vs a Broadway production. Sure, you can make scrambled eggs at home on your stove, but if you've ever had scrambled eggs at a Michelin-star restaurant, you know the difference between home cooking and professional chefs. And it's way more than "mystique".
Matt and Co are professional actors who spend a lot of time on character and story instead of combat and looting. It's character-driven D&D run and played by professional voice actors. They get into character, use voice acting techniques, do more than just fight endlessly, and Matt's a vocal chameleon. He is the man with a thousand voices. They take their time and don't skip over roleplaying opportunities.
I don't know about your experience with D&D, but mine has been 30+ years of nearly endless combat, looting, dungeon crawls, with basically zero character development or larger plot / theme beyond getting to the next room, kicking in the door, and murdering whatever happens to be there.
Critical Role was literally everything I'd want a D&D game to be. The literal opposite of what we'd been playing. But, the people in my group were all fans. They loved CR. Yet they played D&D as an endless brawl. None of us have an ounce of acting or voice talent, but the character-driven game play is what all of us are craving after decades of dungeon crawl and endless brawling.
I can't speak for the rest of the group, but I was ready to quit before I started watching Critical Role. D&D had become a bad version of a video game. Railroad from start to finish, no real character development other than an endless treadmill of loot. Only we had to drive for 30 minutes to deal with a house full of loud people goofing off and not giving a naughty word about the game, talking over each other, not engaging with the game and generally not caring. It was just something we did at that point instead of something really fun and entertaining.
Then we paused, took stock, talked about things and realized we all wanted basically the same thing. A more engaging and character-driven game with more than endless brawls. We basically had Critical Role to thank for something to shoot for and for saving our group. We've played together (on-and-off) for over 30+ years. Would have been a damned shame for that to fall apart.
It's not that we're trying to emulate the show, no one's trying to do voices. There's no negative Mercer Effect of thinking he's perfect and should be emulated or he's the gold standard for DMing...but we are trying more. Giving a naughty word more. Engaging and being present and staying in-character more. Metagaming less. Trying to get something like a story out of the game instead of endless brawls and a loot treadmill.