I feel like it's sort of.... it's either there forever, or it disappears startlingly quickly.
A lot of the webcomics I read as a teen are gone. One ended up being re-hosted by a kind soul who still had all the files from back before the website went defunct, but others like... might be remembered by a few folks who used to read them, or mentioned as a comic that used to be online in some wiki -- maybe you can find one or two pages in the wayback machine if you're really looking -- but only those few traces remain.
I don't think my work lasting past my generation is super important to me. Heck, forget still existing when I'm 70 -- I'll consider myself extremely fortunate if my work is even still relevant when I'm 70. Some of my own comics from just 4 or 5 years ago feel outdated and cringey now -- not just in terms of art, but in terms of what jokes seemed funny at the time. Rereading favourite webcomics from 10 or 12 years ago, there are parts that I still love, but there are also elements of them that have really not aged well, whether that's weirdly thoughtless jokes or just thinking that "teh awesum" is a cool way to spell anything.
To me, the idea of some kid stumbling upon my comic still on the Wayback machine somewhere in 2057 is just passingly neat. But the idea of some kid growing into a 50-year-old who remembers my comic and, even if she can't find it on the internet anymore, still tells her friends about her favourite parts or gets excited when she meets someone else who used to read that comic back when it was online -- I feel like being remembered in that way would be way more incredible.