I think it totally depends on who the reader is. Currently listening to Ed Thorpe’s A Man for all Markets while I walk the dog each day. I wouldn’t say he’s the best speaker I’ve ever heard but just the fact that it’s him has me gripped.
Dan Carlin’s podcasts, I could listen to him all day.
Totally. A poor narrator can ruin the finest author's work. There are some narrators that are superb at characterisation and voicing and can pull you into a story completely. Then there are a lot in the middle and some that make a terrible job of it - yet never seem to fail to get repeat job offers.
Sadly I find Audible heavily over represent the poorest readers and quit my subscription over it years ago.
Author and narrator are equally important when I'm deciding whether to buy. The best narrators have me seeking out what they've narrated and see if there's anything else that appeals.
Dan Carlin’s podcasts, I could listen to him all day.