Although this looks like a strong correlation, looking at the data more closely, there is a difference between the 2015-2019 data and the 2020-2021 data. This is a result of the website the data was taken from including the speed of the player when taking into account their expected batting average.
We can see that each of the adjusted years look mostly the same and each of the non-adjusted years also look the same as each other.
Looking at these graphs, it can be seen that before xBA was adjusted to speed, a player with very high speed (30m/s) can get a batting average of about 0.025 higher than a player with very low speed (23m/s). Although this might seem like a pretty small number, a slow player with a good average of 0.275 can become one of the best in the game at getting hits if they are faster. These graphs prove that being faster can help improve a player’s ability to get hits by a significant amount.