I really like Manjaro. I’ve been running it on my personal computer for many years now, however, I would not recommend it for grandma’s computer. Their “delayed and curated” release strategy mostly just works but when it doesn’t it doesn’t. As someone mentioned elsewhere in the comments I would lean towards Red Hat or Debian for more mindless distros. I’ve administered thousands of Debian package updates and distro upgrades and it’s so stable. We don’t deserve Debian.
No man can walk out of his own story.