The timestamp of the file is too fragile and can be easily changed for a number of reasons. So I don’t think it’s very reliable. And as far as I know, at least on android, there could be a lot of problems with keeping timestamps. So storing the timestamp in the metadata of the notes might be a simple and easy way to do it.
For example, as this fr points out, obsidian’s file sorting relies on the file system timestamp, so once the timestamp is modified for some reason, the timestamp-dependent file sorting will become completely unusable.
My workflow relies on update times, so it’s important to me to have accurate file update times. I now rely on this plugin to maintain the update times of my files
It would be exciting if obsidian could use the timestamps in the metadata to sort the files.
I can imagine that YAML front matter based timestamps could easily implement a lot of workflows about time