"Important" is quite a high bar in this case though if the House of Lords is insistent enough to actually vote something down. The cost in terms of parliamentary time for the government these days of using the Parliament Acts is very high (especially for things which government would normally do via secondary legislation), and it also requires at least a one year delay; by extension the potential political cost to the government of using the Parliament Acts to pass something unpopular or controversial is set at a high enough bar that it's an effective veto.

This feels like quite a sensible safety valve to me.

With a very small number of exceptions, including changing the maximum duration of Parliament from 5 years.