That skill is only of value if you value it.
It’s hard to sight read at a high level. Every high school student I’ve ever taught will confirm this, and most college music majors – especially voice majors.
It’s hard because we start it later than we start reading text. We don’t have years of training from the earliest ages. But it’s also hard because many students don’t value sight reading as a skill worth their time.
If you valued sight reading, you would have much less trouble finding time to develop the skill. But until you value it, you’ll never develop it efficiently.
This is true for so many skills we need for successful careers; if only we took the time to understand their value, we’d be motivated to learn.