This makes sense to me. You should never rely on your CA to let you know that a certificate is due to expire soon, you should have your own monitoring in place that actively checks this for you.
As a hobbyist without a lot of time for sysadmin, it would be nice if basic email monitoring was a standard package (apt install letsencrypt-monitors or something).
Just use certbot. It automatically sets up a scheduled task to renew your SSL/TLS certificates in the background, typically using a systemd timer that runs twice a day. I do not know why people using LetsEncrypt would not set up certbot along with it, that is how I do it. Some nginx config + certbot.