If still we want to keep “collector” word given by Warren Hastings 300 yrs back. Later, Magisterial power was given so that tax can be collected more efficiently. Hence, Collector and District Magistrate.
Post independence, both right to punish and tax collection became responsibility of judiciary, police and revenue services officers.
The primary work of DM or DC became socio economic development of district, executing various development program of central and state government post independence. Other important work is land management including, mutation, transfer and collection of dues of land and other dues as land dues.
While, 73rd and 74th amendment recommends devolution around 30 subjects to local government that includes development and land work as well.
Its high time that role and name of this post shall be redefined as per the constitution of India.