In the United States, many non-towered airports have CTAF frequencies (often shared with UNICOM as well) that tend to overlap with various other airports within a 50-100 nm radius, at least in more populated areas and states. I personally do not find this practical, as it congests the frequency. Also, for every radio call, you have to carefully listen to each call in order to know with respect to which airport the aircraft is calling.
Of course, there are other hints such as runway numbers, but the congestion is still not ideal because it increases the workload, makes it harder for you to say something, and increases the probability of radio collisions. I also noticed that in my area (Northeast USA), the CTAF frequencies are typically multiples of 100 kHz, even though we have a 25 kHz channel spacing system in place.
My question is essentially, why is there such a huge degree of overlap? Are there really no unused frequencies remaining to assign to all these airports? And if the answer is no, how about transitioning to 8.33 kHz channel spacing? Does there exist any plan to have better separation of frequencies at any point in the future? I am not yet an experienced pilot, but I do think that the ability to listen to only your airport and not 2 to 4 additional ones could significantly reduce the workload associated with non-towered airport operations and radio communications.