Exactly for longevity (5, 10, 15 years), I will not use any static site generator. I know it sounds ridiculous, but I have better confidence of longevity on Wordpress / Mediawiki than static site generators.
I recently tried to revive a 2014 backup of my local hackerspace's website so that I could staticize it, but it wouldn't look right even with the same PHP and MySQL versions, because many of the plugins stopped working.
I think I would have been better off scraping a copy of the site from Archive.org.
The same can't be said of WordPress or MediaWiki. You will not be able to run these at all if they become unsupported and will have to migrate, or risk facing security issues.
Sure, SSGs are not for everyone, but the potential for deprecation isn't a major issue, at least for a personal site.
If for some reason all those companies selling and supporting Wordpress would not be allowed to continue using it by magic I am sure they are capable enough to migrate it for me.
My only experience with Wordpress is with a simple blog and not complex sales pages or other stuff that require using SEO/sales/magic plugins. Worst case scenario if you are a developer you can dump the wordpress database into a file then write a script and generate plain html files or migrate to some other format.
Besides a few minor configuration updates, it worked almost out of the box after the upgrade on a new server.
2003 vs 2008
Also I realized another issue with SSG, the setup is on the desktop, not on the server. I have problems with this too.