Hi marcs,
You can read a little more about latex and its durability in this article (which has a video of an almost 50 year old latex mattress) and also in post #6 here. It is certainly a unique material in the world of bedding.
I would keep in mind that most of the stories you hear about latex lasting decades would generally be single layers of firmer latex (softer versions of any material including latex aren’t as durable as firmer versions) but latex as a category is the most durable of all the foam materials. A well made latex mattress that isn’t too soft can last decades yes. Even if you use softer latex in the top layers for pressure relief it will still last longer than other materials and you can just replace the softer top layer instead of the whole mattress because the deeper layers would still be fine.
Phoenix