Reading is a great shortcut to the aquisition of vocabulary, knowledge and all its wider benefits, but it isn't the only path there.
I've produced two dyslexic children who have no great love of trying to decipher wrigging letters squirming around on a page as a form of pleasure. Being children of a book lover they have still benefited from years of bedtime stories, and by proxy gained a lot of the benefits of reading including through audiobooks and kindles to make stories more accessible. It's not the same, but they have advantages over children whose lives don't feature books outside of school which sadly is common, and well documented to be a hinderence to academic success.
DS1 is praised for his general knowledge by his teachers. He did like children's fact books when he was younger and tends to watch a lot of factual content on youtube. The gap on non-fiction sources is probably smaller than fiction.
DH is a (probably undiagnosed dyslexic) reluctant reader. He has a PhD and can read technical, acdememic content in his niche, but seldom reads for pleasure. It's probably not a co-incidence that he also struggles with quiz levels of general knowledge.
A fiction book will contain a greater range of vocabulary and depth of ideas than a screen adaption that lets the visuals do the talking. In the Harry Potter fan community, you can tell the difference between the book fans and the film fans because the books explained so many plotholes that weren't covered in detail in the films.
Pretty much any reading is a good thing. Reading is (generally) great for a state of mental flow and prolonged concentration. For me, smartphones came in at a time of sleep deprivation and nightfeeds which ruined my attention span. In recent years, I've made windows of time to read novels again and it gets easier with practice.
I suspect there is chicken and egg. You don't have to be a book lover/ reader to be intelligent and curious but to be a book lover/ reader there will be a baseline of intelligence and curiosity in the first place, then there are the mental benefits of reading on top of that initial advantage. Books are also an accessible way to gain cultural capital (especially through the wonders of libraries)