Keyword re-targeting on existing content vs making new content

Question about content and keyword targeting. I have content that is ranking for question based queries, something like "Can I Watch TV".

I have an article ranking for "Can I eat melons" on the second page (large traffic volume KW), but it targets "Can I eat guava" (title and h1) which is much lower in volume.

Is it best to pivot the article to target the more in demand keyword (more general KW) or make a new article targeting the general KW and linking the specific article to it?

What is best practice here and what will yield the best results?

I wouldn't risk the current page ranking for the sake of adding a new irrelevant keyword,
If you did rank for such a keyword with no on-page optimisation, then it should be fairly easy to rank for using a specific new post,
Make a new one targeting that keyword and a few of its long tails and interlink it from the old post,
That will be much safer and will do provide a better UX

so the ranking page is a subgroup of the main keyword. Think granny smith -> apples. In this case my granny smith page is ranking for apples but isnt on page 1, but close enough to where google "might" be confused.

I'm no expert so don't take my word for it. But what I would do is analyze the top 5 pages ranking in google for "can I eat guava" and then try to mimic / match their content, I would also link internally from one of the pages of my website that has high PA and which is very relevant to the "can I eat guava" page and I would use "can I eat guava" as the anchor text. If the keyword (can I eat guava) is not very competitive and if you get this exact match anchor + match the content of the top 5 ranking pages in google for this term you should be able to push your guava page to google's 1st page which, I assume, is your goal anyway. And if the internal link + great content doesn't do the trick it can only mean you need more, and stronger backlinks in general (to the root of your domain, but also a few of them to the guava page).

As for the other keyword (the one with lots of search volume) I would create a page targeted at this keyword and see what happens. If this page skyrockets to pages 1-3 of google just by putting good content (again, content that matches the content of the top 5 pages ranking in google for this keyword) on it then a few good backlinks should be enough to push this page (the melons one) to google's 1st page. If not... well, more and better backlinks will definitely be the solution

But the point I'm trying to make is that you should leave the guava page alone and create a new page for the melons keyword. I have no idea why google ranks the guava page for the melons keyword but I have a suspicion that neither google knows this, either. Sometimes google is more drunk than a drunk on drugs, so I'm not surprised...