And it’s not like crops would be smaller in the shire.
This is true but if we're going to engage in this sort of biomechanical analysis, hobbits being so much smaller than humans (and thus much slower and with far less reach and so on - more than D&D accounts for) would be drastically worse at planting and gathering crops as well. Where they could get animal assistance (which we know they use), they could get closer to human performance, but they'd still be distinctly behind overall. That's without accounting for work ethic or anything else of course.
It might be by so much that they aren't even coming out ahead, with their constant eating and large appetites. There are too many variables to be sure, but I suspect they're not hugely protected from starvation by this.
At least they probably produce a lot of... er... fertilizer. It's got to be going through those little hobbits and out the other end pretty quick!
All that said, the Shire sure has the vibe of a place that hasn't experienced starvation in living history, and starvation is very often due to wars or climate issues, neither of which seems to have recently impacted the Shire. According to Tolkien the Shire has mild winters with snow being rare, and warm summers with frequent rainfall, so they probably have more viable growing time than most places. They also seem unlikely to overfarm, and may well be familiar with proper crop rotation and the like, which would keep yields up. Especially without much trade, their incentive to do "stupid stuff" with farming is very low. And yeah let me actually add to - that a lot of the worst starvation incidents in history are not due to war or climate, but rather trade and empire, particularly those two combined, and again, the Shire isn't really subject to either.
