Ah...the fretted instrument. They have been around for centuries. They have so many benefits like easier note selection, the ability to more easily play chords, and a visual way to divide the fingerboard into easier to digest sections. That being said, there are a couple of drawbacks. While potential buzz is increased, we have already covered that topic, so we will be talking about the other main issue that has been driving guitarists insane for years. Intonation. Or the lack of having perfect intonation. With many instruments, intonation is paramount to being taken seriously. In the world of classical and orchestral instruments the intonation is up to the musician. With guitar.....well...not so much.
Intonation is the "accuracy of pitch in playing or singing, or on a stringed instrument such as a guitar".
The guitar being fretted, while having several very distinct advantages over non-fretted instruments, has one fairly big flaw. It cannot be intonated perfectly over the entire fretboard. You can see this when you play through several chords and can hear that they are all just a little out of tune. You can also try to tune a chord (say G) to be perfectly in tune with itself. now when you go to play an A or E you will be out of tune. This is normal and is an issue that has been around since the very first fretted instruments. Setting the intonation is a combination of adjusting the length of each string as well as ensuring the string and nut slot height are also correct.
A properly intonated instrument will be very close, but never perfect. That's ok. It is part of the instrument. While there are some attempts to correct this issue (true temperament frets), the guitar has been around a long time and all of our heros had the same shortcomings. Of course, you could get a fretless guitar.....