With anonymization or masking, one manipulates original data to hinder tracing back individuals. For example, one deletes parts of the data, generalizes the data or hussles rows and columns. If you do this to a small extend, it can still be possible to regenerate original parts of the data, which triggers privacy risks. If you do this more thoroughly, you destroy your data and lose valuable data quality and business logic. Since this trade-off always exists, anonymizing or masking is not a great way to go, since it results in a sub-optimal combination between incurred risks and data quality.
Moreover, we see that this is often a cost- and time-intensive process, because these techniques work different for each dataset and for each data type. This introduces internal discussions about how to apply these techniques and the level of risk mitigation that you must achieve. Since the data format changes frequently, you must start-over again.