Collectively we do tend to be sloppy with language.
English, like any language, is dynamic and never static. The word Gay generally isn't used the same way now that it was in 1920. I don't get to attached to any one definition over the long term.
I agree. The point, though, is to have at least one word that means what no other presently used word really means:
in this case, the total of all that presently exist, anywhere.
Even if we say "at this time,"
that time is in units determined by the simultaneous spinning and orbiting of one very specific planet around one very specific star.
Even if star and planet both cease to exist at some point, the units of time which they created still historically remain unchanged.
The time element isn't subject to discussion just because we know that we're using the concept of time
in such a highly restrictive manner. We know and understand what we're using.
No scientific principles are challenged by the concept of "everything,"
unless you choose to challenge the concept of everything itself,
in which case we couldn't communicate at all
because I see no complexity at all in the concept of "everything."
There should be no problem in having a word to mean everything that exists in any manner or form of existence.
Would it be better to have to say
"everything that exists in any manner or form of existence?"