Certbot isn't the only acme client in town. I use Chef personally: https://github.com/schubergphilis/chef-acme/
Professionally, it's not once every three years, it's that x the number of clients we host. Which is a lot. Many are clamoring for LE, because it's within their budget: $0. So yea, I want to automate that.
I have another cronjob that fits the same description, runs daily, and it's called "unattended security updates". Just saying.
Edit: Also, it's a persistent myth that certbot needs to run as root. It most certainly doesn't on my servers.
Is this really what i am reading?