They're even more exploration-heavy than Emerald. Roughly, the earlier the game, the bigger the focus on exploration, as hardware limitations didn't allow much storytelling.
Also, I recommend playing their remakes instead of the original games; the originals are extremely buggy and have huge balance issues. (For example, there's a shore in Red/Blue that you can use to catch Safari Zone mons. And Psychic mons are crazy overpowered - the only Ghosts in the region are partially Poison, there's a lot of other Poison types, and since Gen1 was before the special split they got huge offensive and defensive capabilities.)