I used Rick Steves guidebooks for my first trip to Europe some 26 years ago. Not all inclusive, but some thoughts:
Rick Steves "Europe Through The Back Door" is an invaluable resource. Part guidebook, but mainly just good basic education on how to travel independently. How to use trains, money matters, how to do just so many things not being covered in most guides. It really should be your first reading on the subject.
Maybe the biggest complaint that comes up is "Why doesn't Rick cover City XYZ?" The guidebooks cover the major tourists cities in a country, plus some select smaller cities, and that is OK. You mentioned being overwhelmed, imagine if a guidebook was like an encyclopedia of a country? While Rick's guidebooks have their limitations, they are more than sufficient for a first time traveler, more seasoned travelers gain skills that allow the to find their own "back doors".
Guidebooks are becoming less a valuable tool than they once were, industry wide, not just for Rick Steves. Even the RS org used to make a big deal of updating books yearly, now, well, every few years is the norm, just like the few other guides that are still in business. Guides can still give good info on the major sights, transportation, and the best areas to stay in. They are less valuable these days for hotels and restaurants. Maybe some decent recommendations, but I find Booking.com and my IHG app better for rooms, food blogs and Google searches better for restaurants.
Other than that, the audio guides and walking tours are very good for the areas they cover.
Rick Steves attracts a certain demographic, a bit older, upper middle class, and that is reflected in the choice of what is included in the books, from hotels to sights. If you fit that demographic, then everything will click, if not, you will then need to adapt. If you are much younger, then you may have to seek out other attractions and activities. If you are more "budget traveler", then you may need to seek out other lodging options.