Sorry for yapping, but this is a very perplexing problem that even we as a collective civilization struggle with. For example: how do you keep future generations out of nuclear waste vaults on a 1000/2000/1`000’000 year scale (we don’t even talk about infinity, because it is surprise infinite times larger), because we cannot predict how even our language and (more than that) our culture would look like. One text/symbol/pictogram could tell something completely different to a person 10000 years in the future, than to a current-day one.
For me, the most interesting part was the conclusion: instead of using static language or pictograms printed on the walls (although some menacing skulls wouldn’t hurt) they instead opted out to a more dynamic and “updatable” forms of media - myths and legends (and maybe also a church, but I don’t remember). And that is not as ridiculous as it sounds - some of the myths from the past that we can read, like, right now, were created more than a couple thousand years ago (some even more than 10000). Also, an obvious note, but they weren’t created in a modern language. So this means that everything around them basically died/changed: the author, many many many of the ones who retold them, their first written forms, the printing company that first printed them, even the language (basically, transmission protocol) on which it was created is dead.
So (if we get back to the original scope of the question) that means that you basically have two choices:
Make your web site out of stone and hide it somewhere around Antarctica.
“+”:
the decay would be greatly slow down
no one is going to (or, could) delete/destroy it
“-”:
no one is probably going to see it for a looong time (and when the do, they might not understand a thing)
Not be silly.
The thought of everything that you do/have/see breaking to dust is equally scary and relaxing - but it is true. No matter how much you paid for your domain name, or how your server is getting power out of solar, self-backups and self-repairs - everything eventually would break, catch fire, explode and turn off.
Or rather it will, without someone maintaining it. Because the only man-made things that live forever are doing so on the power of human resilience and preservation. It’s like this ancient art of a horse on some hill in the UK, that would be erased by the tides of history a loong time ago, but is still here because a couple of english mates have a bucket of white paint and some free time on tuesday.
So if you think about how this site that you poured your heart and soul into would instantly vanish as soon as you’re dead, remember: as long as someone cares and loves what you do (and with some coordination), the thing that you made would transcend the boundaries of some hostings, domains and internet protocols (and maybe even the language itself) and live in the minds of people, truly, forever.