There's studies showing that LLM makes experienced devs slower in their work. I wouldn't be surprised if it was the same for self study.

However consider the extent to which LLMs make the learning process more enjoyable. More students will keep pushing because they have someone to ask. Also, having fun & being motivated is such a massive factor when it comes to learning. And, finally, keeping at it at 50% the speed for 100% the material always beats working at 100% the speed for 50% the material. Who cares if you're slower - we're slower & faster without LLMs too! Those that persevere aren't the fastest; they're the ones with the most grit & discipline, and LLMs make that more accesible.