However, an increase in computing quality doesn't necessarily mean an increase in output quality, as you need compute power + data to train these models.

Just increasing compute power will increase the performance/training speed of these models, but you also need to increase the quality of the data that you are training these models on.

Maybe... the reason why these models show a high school level of understanding is because most of the data on the internet that these models have been trained on is of high school graduate quality.