I use gentoo on 3 computers and I do not spend more than some hours per week maintaining it, which is ok for me. This includes compile time, where I just wait for the process to finish and do something different. First gentoo installation was very hard, the two others were much more easy because I understood emerge's output better (emerge is the package manager). But gentoo installation is a one-time thing, once installed it gets upgraded forever.
I was looking for a rolling release distro and I got what I was looking for. Also: A little bit on the conservative side in deciding when to put a new version into "stable", which is a good thing (30 days without bug report are the default). And the best online documentation of any distro I ever used.
With rolling release, sometimes manual work is required on major version changes of an important software, but the necessary steps are documented in elogs. Manual edits in several config files needed when I want something different from default - yes, this could be better.
Gentoo can break when it is not updated at least every 2-3 months, because older versions of packages rotate out of the package tree and there might be no tested upgrade path from something-1.1 to something-4.5.
But to start installing and maintaining gentoo, one should at least have basic knowledge of where things are in a linux system, how to work with command line and text editors, and have a second computer with internet access for the installation guide.