The standard deviation of mean addition and subtraction is point estimation, and the sample mean is directly used as the point estimation value of the population mean. The standard deviation reflects the difference between the measured values in the sample, that is, the degree of variation. The greater the standard deviation, the greater the data difference, indicating that the sample you selected may be unstable, or the representativeness is not good, which may not truly reflect the overall parameters.

The 95% confidence interval of the mean value is interval estimation, which overcomes the shortcoming of point estimation considering sampling error.

In the paper, both can be used.