The question
When an existing page is worth investing in rather than leaving, replacing or deleting.
You have a page that under-performs and are deciding whether to invest edits in it.
Why it matters
Time is limited and not every page repays optimisation - some should be left, merged or removed instead.
How to decide
IfIt ranks on page two or gets partial citations for a valuable query
ThenYes - it is close; optimise it (highest ROI case).
IfIt targets valuable intent but is thin
ThenYes - deepen it against the Knowledge Coverage Model.
IfIt duplicates a stronger page
ThenNo - consider merging instead (see Should I merge these pages?).
IfIt has low value and no path to relevance
ThenNo - consider deleting or consolidating.