Yes. The whole post is a trick with statistics. Web pages have a limited lifespan. You can do the aame trick with human life spans.

“50 % of humans that lived 60 years ago are now dead”. You would tweak the numbers to be factual but something like that makes sense to me.

If you only keep the samples you started out with, of course it’s going to decline over time. The data is guaranteed to not grow since nothing is ever added.