(Circular) buffers are architecturally beautiful.
This is because when interrupts are used the main program and the interrupt code are manipulating different parts of this shared resource. It is possible to code the buffer in a way that interrupts can be left running while checking the buffer contents. This of course assuming that the buffer pointers are one byte wide thus making their read and write an atomic operation.

(Circular) buffers make Your code more reliable.
A general rule of thumb in embedded coding is that one should keep the hands off the hardware unless really needed to fiddle with it. The ring buffers are memory elements - not hardware so polling of those does not have any unwanted side effects. Further more, the hardware access occurs ONLY as needed.

(Circular) buffers allow more readable programming
As Your design is freed from strict timing limitations of direct data port access You can design Your software with more freedom. This should lead into more readable and architecturally beautiful result. Although coding is not the beauty-contest it is not a bad idea to put some effort on standardising the code.