When reading through the other Planes of Existence as they're presented in the DMG, they rarely provide enough detail to confidently build stories in those locations or confidently describe what the PCs are experiencing. The Infinite Staircase remedies this with the style and level of detail indicative of Oliver's work. The Planes Landings, their varying themes, and the plethora of tables Oliver provides hit that sweet spot of enough structure to outline a story while giving DMs the freedom to effortlessly incorporate these alien lands into any campaign.

If you're serious about including planar travel in your campaigns, do yourself a huge favor and pick up The Infinite Staircase.