In On Writing (p. 147), Stephen King says "Reading is the creative center of a writer's life."
We develop our ear for language through reading. We learn the craft of writing - how stories are put together, what works, what doesn't, how much description we like, what makes a character come alive.
As a kid, I spent entire summers in a tree reading. I had full access to my grandfather's sets of O'Henry, Dickens, and other writers from that era. My adult siblings left collections by Serling and Hitchock lying about, and Mom's historical romance novels were fair game as well. And of course there was the library.
As a college student, I had to read texts and other material - thousands of pages every week - and still worked in an occasional novel for relief. As a working mother on my own with three challenging children... well, it got a little harder. They did provide me with a lot of material, but I looked forward to our camping trips because I'd grab a stack of paperbacks at the grocery store and read them by the fire at night once the exhausted kids were quiet in the tent.
I am probably a little OCD. My kids knew, if Mom's reading a book, leave her alone unless it's a crisis. I finished all 849 pages of 11/22/63 in one weekend - and I read every word. I just didn't stop except for essential breaks. (The kids were grown and I was living alone - made it easier.) I like to stay in the story through the end.
It's not always possible to do that. However, I almost always have my phone with me - which means I have full access to the world of literature via my library app. Whenever I have to wait, instead of being impatient about wasted time, I open my phone and read that book I want to finish.
So, if you're serious about writing, read. If you're busy, use those scraps of time and know you are feeding your creative center.