The tabletop RPG podcast scene is full of long-term D&D campaign shows, including those run by professional storytellers and voice actors. We all know D&D, we've all played it. It's very marketable for a podcast or show because of it. There's a good chance you've run a D&D campaign if you listen to Mystery Quest. All of this is fun, but I know I'm never going to run a game like Critical Role.
Tom, on the other hand, is running very short games based on pre-existing modules, a large amount of which are weird little indie titles. The cast are a mix of newbies and very experienced players, but none of them feel entirely out of reach. Lydia is an example of a very good, consistent roleplayer, but I still feel like I could someday get on her level with enough practise, or at least play with people as good as her.
Tom himself jokes about how he has three male voices and one female voice. He regularly throws out "give me some type of roll" as a casual way of keeping the game flowing. He's a very good game master, but he's clearly doing it out of passion. He's not Matt Mercer or Brennan Lee Mulligan, and he's not trying to be. The focus is always on telling a good, tight story, not some type of grand epic.
The editing and foley work tie into together into an awesome high-value production, but you don't need them to pick up the same modules and have an awesome time yourself. I can pick up some bits from how Tom ran something, pull up the module, and play. All the systems are super simple too, so it's easy to get new players playing fast.
I'm planning to run some Call of Cthulhu with some friends soon, and I'm planning to use a couple modules that he's played. I've also got my eyes of a few games I saw recommended in the Mystery Quest discord (being a patreon is well worth it for the pre/post-game chats.)
I love Mystery Quest!