Automation is a tricky thing, and from a purely mathematical standpoint you can easily calculate whether automating a task is worth the effort. See the classic XKCD covering this topic:
To summarize, all you need to do is look at how often you do a task and how much time it takes, to determine the amount of time it’ll save you. Then you can look at the effort of automating to determine whether it’s worth your effort.
Though I believe this is a simplistic view and automation how more benefits than time savings…
Cognitive Load:
Any task that is automated is instantly removed from your cognitive load. There is a finite amount of space in your working memory and automation helps clean that up. I look at paying bills each month as one of those things that only takes a few minutes to do, but they cognitive load of remembering to do it is to expensive for me. I would prefer to automate it and never have to think about it again. Even if the time savings may or may not justify it.
Mental Fatigue:
Manual tasks are taxing on the mind and with cognitive load, there is also a finite amount of energy the brain can utilize each day. Manual tasks burn energy that could be spent doing things that derive pleasure and thus increase your sense of overall satisfaction. This benefit alone makes automation well worth the effort in many cases depending on the enjoyment you get out of specific task.