https://www.youtube.com/watch?v=u6hg8GcLc-4
Scales are the very basis of almost all music. While it is true that anyone can learn a piece of music without knowing any of their scales, for example using popular methods like YouTube, Yousician and other modern learning platforms, if someone wishes to become an actual musician and take it seriously then scales are the basis of everything. Scales are important for all of these below - this list is not exhaustive:
Dexterity - being able to move your hands quickly and fluently around your instrument
Constructing and understanding chords and melody - again anyone can play chords without knowing scales BUT they will not necessarily know how they constructed those chords
Relative pitch and being able to hear and understand music without an instrument present
Composing music - with intention
There is an infinite list of skills and fundamentals that scales lend themselves to in music, but just the above short list covers so many fundamentals of playing music. For example, dexterity allows the playing of melodies and complex broken chord arrangements; understanding chords is important when accompanying especially in contemporary music, pop and jazz.
Major
Minor (natural minor)
Chromatic
Major Blues
Minor Blues
Technical exercises are crucial to master the guitar. Think of a footballer. They don't just play games but instead they actually train more than they perform. A Premier League footballer would usually play just once or twice a week. They would train a minimum of four or five days out of that week. The same applies to musicians - you should train more than you perform, and certainly train with exercises more often than you play songs that you enjoy.
Here's a video from him on practice tips for beginners - https://www.youtube.com/watch?v=wHnO1CWf5RA&t=97s
Practising with a metronome video - https://www.youtube.com/watch?v=FLgq5VPRT6k