For many of our apps, they are not simply opened, used and closed in quick succession, but may instead be open for a long time or even be pinned as a browser tab.
If the user has applied a filter to a table, it’s hard to know that this is the case – it seems as if there are simply fewer total rows than usual. For a filter that was applied a little while ago, it can easily be forgotten about. This has happened to me multiple times, and would especially be confusing for non-power users or for shared computers.
It would be good if the filter icon or other visual cue would stand out clearly if a filter has been applied.
For an example of this, see the filter functionality of Airtable, which has a similar setup and has a striking visual cue when a filter is applied vs not.