Inside the realms of "it's just complicated d&d" thinking of course an unelected, long lived upper chamber is like a pressure release valve combined with a rusty gate, and so inherently useful if you want to push back on lower chamber acts and make a lot of noise doing it.
That effect is less visibly useful when it's peers objecting to Voluntary Assisted Dying legislation on the grounds "my nanny doesn't like it"
(I know peers, both life and inherited. I believe many from both camps are serious people of good intent and significant skills. That doesn't negate much of what I said above)