Hi Martha
What is "making a difference" to you? How exactly is it that you want to help the world?
I think you need to start by defining what you want your writing to accomplish, and what you want people to take away from your writing.
Before you get too settled into your opinion that telling people where to get a cheap room or find an all-you-can-eat buffet is somehow not important, consider that there are a lot of travelers that need that information, or else they would not be able to (afford to) travel. A lot of travelers seek out that type of information through guidebooks and online resources.
That doesn't necessarily mean that you have to write that type of content. You should write what you find fulfilling.
It may be that writing about travel isn't going to work for you - you may decide that to "help the world" you would rather write about human rights abuses, or poverty in America, or some other subject that you find personally gratifying.
But keep in mind that it ALL matters to someone. Find ways to encourage conversation through your writing.....that will give you an idea of whether or not you're making a difference.