I have semi-recently converted a couple of Wordpress and also Docuwiki sites to static sites. First with Hugo, then converted again from Hugo -> Jekyll.
I could not be happier with the results (...with Jekyll anyway, less so with Hugo). And there is no npm.
The biggest problem for me was mentioned in the article - security. It felt like I was frequently having to babysit updates in Dokuwiki and Wordpress. Both of the update procedures felt precarious and dangerous - more than once they'd fail to update and hose something on the server and I'd need to go in with a SFTP client or SSH and try to rectify whatever the hell happened. I grew to fear the updates and started to procrastinate doing them which was a warning sign. Perhaps they are perfect and flawless these days?
And even when I had updated there was always this lingering feeling that there was some unknown/unpatched exploit or I was 12 hours too late patching and so someone was "inside" my wordpress running a spam/phishing operation without me knowing (happened to me, but perhaps 15 years ago now and was due to the hosting provider so not really relevant... I only found out about that one when a victim of the phishing operation did a whois on the domain and sent me threatening messages. Nice.)
These sites that were on Wordpress/dokuwiki didn't even need to be "dynamic" anyway - they just needed to serve content and provide a simple way for people to edit the content. Github pages does a great job for this - non-tech users just use the in-browser editor and if they accidentally delete something there is the git changelog. The time "lost" to do a one-time compilation of the site is totally paid back by the near instantaneous loading time compared to the bloated feel of the previous sites waiting for PHP+MySQL to do its thing on some VPS or shared host (I did not have a CDN).