When you buy imported rice in the store, there are often rows of tiny holes punched into the plastic bags. What is that for? Doesn't it contribute to spoiling and spreading of bugs?
The holes let the bags breathe, so they can be compressed without popping, and packed more densely. Spoiling and spreading bugs aren't generally huge issues. Rice doesn't really spoil or go stale or anything. (I suppose it can go rancid, especially brown rice, but it takes a long time, and keeping it airtight doesn't prevent it anyway.) The holes are likely small enough to keep bugs from getting in easily, and determined bugs will eat through airtight bags anyway.
Not all rice is packed this way. Sometimes you'll see it in fabric/burlap bags that have holes naturally, especially for bigger bags. It's also common to see paper bags kind of like flour which don't have a perfect seal but don't have holes poked in them either. And for smaller quantities in American grocery stores, I've seen a lot in airtight plastic bags without much extra space.
Rice isn't the only thing that gets this treatment. Another common example is frozen vegetables. Despite the fact that it does actually allow faster drying out (freezer burn), it's apparently worth it to keep the bags from popping under their weight.
So, for some things airtight bags are desirable. For example, they keep chips from being stale and resist compression that'd crush the chips, which is well worth the downside of looser packing and possible popping. But for rice, those upsides don't really exist.