What he said. We often just browse the guide to see what's on, and often find things that are interesting we'd never know to look for. That includes movies, documentaries, or just TV shows that look interesting enough to hit the "record this episode" button to see if it's something we'll like.
Lack of a good guide system is a major negative for us. My son has YTTV and it doesn't bother him but his TV watching style/habits are different than ours; he watches sports and a few shows that are favorites and shows for his children and overall doesn't watch as much as we do.
There are online TV guides and mobile apps that allow you to select YouTube TV as your provider so you can search further ahead. I know that's not as convenient as having all that info within the same app, but it's an option if browsing ahead is such an essential function for you.