Dry yeast reportedly loses around 20% of its viability per year when stored at room temperature, compared to 5% when stored cold. If you're buying and using it within days or even weeks, I guess that wouldn't matter. But if you're buying a few at a time and taking months to use them, you'll have a lot more live cells if you keep it in the fridge.
Hops will depend a lot on how they're packed. The better the packing, the longer they'll last no matter how you store them. I've bought hops in thick, vacuum sealed plastic bags that were stored at room temperature at a wine supplies shop that was pretending to also be a HBS. They were cheap, and I half expected them to be cheesy upon opening, but they were perfectly fine, and smelled (then tasted) like any other Amarillo I've used.
I've then bought hops at a well known, respected HBS where he just tipped 100gm of Cascade into a zip lock bag and passed it over. They were also fine...but they went straight into the freezer when I got home.
As a habit now I store all my yeast in the fridge, dry or liquid, and all my hops in my freezer. The hop pellets must have very little moisture in them because you can hardly tell they're frozen when you take them out.
There are some brewers on this forum (and others) that store their dry yeast in the freezer, and report no ill effects. But if dry yeast loses only a few % of its viability a year in the fridge, I don't know why they bother.