In popular music, the past three generations didn't really need music theory. Many successful musicians and songwriters thrived in the music business without it. Think about your favorite artists from the 60s through the 90s - many couldn't read a note of music!
But, as the famous Bob Dylan crooned in 1964, "The Times They Are A- Changin."
That Bob Dylan song is more relevant today.
Now that technology and AI are transforming the music business, many tools have been developed that include advanced functionality specifically designed for musicians with music theory skills. In other words, reading music is now an asset in today's music business economy.
I'm not saying you cannot succeed without theory knowledge, but it certainly helps to know music theory when you're working in a digital audio workstation (DAW). These programs now have arrangement and chord features that become much more powerful when you know exactly what you're doing with, for example, seventh chords, major chords, or diminished chords or any other chord in the music spectrum
Understanding common standard arrangements makes a huge difference as well. Being able to intentionally switch between a I-IV-V versus a ii-V-vi-I progression gives you creative control that random experimentation simply can't match.
So, music theory matters.
Of course, there will be many out there who disagree with me, but I would challenge all of them -- those with limited exposure to music theory-- to take the time to learn some of the functionality in modern music software.
Consider what it means to write a song in 4/4 time or in 3/4 time or to interpret a syncopated rhythm using 16th and eighth notes written out in notation. Or to know that a dominant seventh Chord always leaves the listener waiting for something more. When you have these skills, you can do a heck of a lot more than if you don't!
The future musician needs both creativity and technical knowledge and, in my professional opinion, music theory knowledge. As AI continues to integrate into our creative tools, understanding the language of music gives you an edge that intuition alone cannot provide.
So even if you've gotten by without theory so far, consider adding it to your toolkit. Your future self will thank you.