Blues guitar is kind of the odd one out in terms of the field of music, its one of the few styles where you can get by quite well without note reading or theory. Everything changes if you have a horn section in your blues band though. Music notation exists to facilitate people with different instruments playing together.
As someone who learned the same way you did, on tab and modern pentatonic blues riffs and improv, but over time learned (still learning) more theory and reading music, I’d recommend learning more reading & theory because it really seriously expands on what you can do with blues guitar. A lot of early blues and pretty much all jazz don’t stay in the pentatonic scale rut, they move around and mix other scales. It’s really helpful to know which diatonic scales you can seamlessly blend with pentatonic, and the reverse: when you can blend pentatonic into a modal song structure, just for two simple examples.
BTW 1/4 tone bends are definitely in the traditional system, they are common even, and in fact are quite directly related to what this article is talking about. The “blue note” in blues is a well known microtone example, but microtonal music in general has theory and notation hundreds of years old, there’s a lot of stuff taking these ideas to new levels. Wikipedia’s article is just the tip of the iceberg, microtonal music history is bigger and broader than this suggests: https://en.wikipedia.org/wiki/Microtonal_music
As someone who learned the same way you did, on tab and modern pentatonic blues riffs and improv, but over time learned (still learning) more theory and reading music, I’d recommend learning more reading & theory because it really seriously expands on what you can do with blues guitar. A lot of early blues and pretty much all jazz don’t stay in the pentatonic scale rut, they move around and mix other scales. It’s really helpful to know which diatonic scales you can seamlessly blend with pentatonic, and the reverse: when you can blend pentatonic into a modal song structure, just for two simple examples.
BTW 1/4 tone bends are definitely in the traditional system, they are common even, and in fact are quite directly related to what this article is talking about. The “blue note” in blues is a well known microtone example, but microtonal music in general has theory and notation hundreds of years old, there’s a lot of stuff taking these ideas to new levels. Wikipedia’s article is just the tip of the iceberg, microtonal music history is bigger and broader than this suggests: https://en.wikipedia.org/wiki/Microtonal_music