They’re not in charge of the project any more than any other project/product manager.
Somebody else is still making final go and stop decisions on their projects, setting their budget, demanding stupid details, etc. They’re just in charge of wrangling some of the creative and production processes and get to take credit for the overall creative vision of the project (or blame their execs/peers/staff if they’re unhappy with it). Literally the same as in any other industry.
I don’t know why I keep replying, but any reasonably social 40+ adult who had lived in SoCal personally knows showrunners as well as people in most other roles in the industry. Some have even held some of those roles! This isn’t some made up basement-dwelled bs that I’m sharing with you; this is actual ground knowledge.
I don't think you understand what a showrunner is.
The showrunner is in charge of the stop-and-go decisions, the details, spending the budget allocated by the studio. They hire the key crewmembers (DOP, lead writer if not the showrunner, casting director, etc. who then build out the cast and crew. They are as in charge of production as they choose to be: some showrunners micromanage, while others let their crew have a relatively free hand to do their jobs.
Of course the studio (usually) has final approval; they're paying for the show. But that doesn't mean the showrunner isn't the boss. It just means that...like every CEO...they still answer to the person with the piggy bank.
Also, showrunners aren't as common as you seem to think they are. You might be mixing up showrunners with producers? Producers are as common as weeds. Frequently, writers and cast members are given producing responsibilities and credits for an episode or two, as are many investors, and generally anyone who handles a task that is in any way related to production and has the leverage to demand some sort of credit.
You might be confusing a 'runner' on a show, which is an entry level production position with 'show runner' which would be the person in charge of the entire show.
Somebody else is still making final go and stop decisions on their projects, setting their budget, demanding stupid details, etc. They’re just in charge of wrangling some of the creative and production processes and get to take credit for the overall creative vision of the project (or blame their execs/peers/staff if they’re unhappy with it). Literally the same as in any other industry.
I don’t know why I keep replying, but any reasonably social 40+ adult who had lived in SoCal personally knows showrunners as well as people in most other roles in the industry. Some have even held some of those roles! This isn’t some made up basement-dwelled bs that I’m sharing with you; this is actual ground knowledge.