Then why all the opposition to what's being said about Rangers? Rangers don't get lost. Full stop. That means that if they have a known destination, they will get there, and they will get there faster than anyone else. If it's an unknown destination, they will still be able to search faster than anyone else. IOW, having a ranger in the party will either bypass or greatly reduce the challenge of an overland exploration challenge.
I mean, I saw it in our Curse of Strahd game. The Ranger had Forest as favored terrain. Guess what? 99% of Barovia is forested.

It made overland travel between points in the campaign pretty much automatic. Few levels later, add in Mountains, and you've got the entire campaign covered. Easy peasy. So, this whole "it's hard to get around thing" part of exploration became a moot point with the addition of a single character.
Now, as a DM, you have a choice - either lean into it and accept that this particular challenge isn't really a challenge for this group, or, as so many in this thread have suggested, you start screwing over the ranger player and nerfing his or her abilities to justify your adventure.
I know which option I prefer.