Why is it more practical to use the probabilistic regression model rather than the deterministic model?

• The deterministic model contains the true values of y, which we need to obtain the best-fitting line
• The probabilistic model contains the true values of y, which we need to obtain the best-fitting line
• The probabilistic model includes random error, which is necessary because the values do not fall on a straight line
• The deterministic model includes random error, which is necessary because the values do not fall on a straight line