There’s been some discussion about the challenges of managing large numbers of automations.
For what it’s worth, I have loads of them, and I have an ‘automations’ directory containing files which group them, mostly, by the rooms to which they apply.
Then in configuration.yaml, I have two automation lines. One brings in automations.yaml (for the three toy automations I created in the GUI as an experiment) and one which brings in all the files in the directory (where the dozens of important ones live in YAML 
).
automation manual: !include_dir_merge_list automations
automation ui: !include automations.yaml
This has worked very well for me for many years: having multiple files is a nice way to group things and, of course, in YAML you can include lots of comments to remind yourself of what different bits do.