Conversation so far:
What are the main roles of Hereditary peer?
As of 2019 there are 814 hereditary peers: 31 dukes, 34 marquesses, 193 earls, 112 viscounts, and 444 barons.
Who are the House of Lords and their connection to Hereditary peer?
The House of Lords, also known as the House of Peers and domestically referred to simply as the Lords, is the upper house of the Parliament of the United Kingdom.
Are there any other ineresting aspect about Hereditary peer roles besides the House of Lords?
The Government reserves a number of political and ceremonial positions for hereditary peers.

Question: Why is that?
Self-contained rewrite: Why does the Government reserve a number of political and ceremonial positions for hereditary peers?