Guitar frets that cut
from the sides are a result of the wood of the neck shrinking over time while the metal frets stay the same length. All guitars do this, regardless of the quality / appraised value of the instrument / how cool it is. Once your guitar reaches this age, carefully use a steel chisel file like the one in the photo below to file down the frets from each side of the neck. Position the file as shown, ensuring that the file is always touching at least two frets at the same time. This is how repair shop Ant Hill Music makes the finished product smooth:
This is how a professional would do it if you brought the guitar into a shop, and it takes about three minutes. Just be careful not to file too deeply or you may need to buy another guitar neck.