All bills except finance bills need the consent of both houses to become law. The Lords can delay a bill for an entire session even though it normally gives way to the elected Commons at the end. Even if you abolish the place you will certainly need that. They are, as it were, repenting at leisure and with an experience largely unavailable in the political factory down the corridor. The intolerant rejection of the elected government's pledge to abolish section 28 is, alas, but nevertheless, just one instance of the power of the House of Lords.
Most successful democracies have a second chamber.
There's a broad acknowledgement that a back-up, a pause for thought from a different constituted assembly is at least useful and at best a necessary check. The current House of Lords can also be extremely positive. It was the Lords that intervened to ensure that all political parties should get at least one free mail shot in the London mayoral election. Then there are the law lords and the scrutiny of ministers handling European Union business. The current composition of the Lords provokes outrage on all sides, it seems.