Disclaimer
Is this project open source? N/A, not source code
Is this project completely free? Yes
Is this project made with AI beyond the author’s ability to comprehend how it works? No AI
For an “all files” / “recent files” sidebar without plugins, search Path:/and sort the results by Modified time (new to old). Bookmark the search for easy access. It lists all filrs because Search has no date operators, but lists them quickly; tho sometimes when scrolling it loads a little slowly.
This is nice when I want the “everything in 1 folder” experience without actually putting everything in 1 folder, or for when the sensible default of 10 recent files isn’t enough because I’ve touched a lot of files. It’s not a great solution if you use Search a lot, but I only use Search on odd occasions when Quick Switcher isn’t enough.
Further details
Searching just / works too but is slightly slower.
The slash should start a regular expression. I’m not sure if a list of filenames (only filenames, even when previews are enabled) is the intended result. It may be a quirk or an undocumented hardcoded thing. But for now it works and is useful.
Other ways
Another way to see recent files is to open the Quick Switcher: it shows the 10 most recent files when the text field is empty. The sidebar search shows more than 10. It also only shows file names; Quick Switcher adds the folder paths in front of names, which can be useful info but makes it hard to scan the names (relevant feature request: Quick Switcher: deemphasize path to match aliases and link suggestions, or hide it - Feature requests - Obsidian Forum).
There are also plugins: