And......?
Not failing to exist is not the same as always existing.
I ‘m afraid it does.
Back to mindless idiocy.

Also noted the editing out of most of what I said, presumably because you have no answers to it.
When you and I die we fail to exist, when uranium decays, that entity fails to exist.
Drivel. We fail to
continue to exist beyond a certain time. Having a boundary in time is no different from having one in space. None of this changes the fact that we haven't failed to exist
The universe we observe is a collection of things that have failed to exist...
It's a collection of things that manifestly haven't failed to exist but most of them to not extend through all of space-time. The actual space-time manifold, of course, is the background against which you are trying make silly claims about failing to exist. You are using a physical part of the universe as a yardstick to measure existence, which is actually quite funny considering you're trying to argue for something beyond the physical universe....
...which is why I ask you “What is it about or in the universe that does not fail to exist?â€
The whole thing and every single part of it.
At the end of the day this is a rather pointless argument about semantics. It doesn't matter one iota to the foolish nonsense that is the argument from contingency and the illogical, incoherent fantasy of a 'necessary entity'.