Could be helpful to be able to engage a function (or mode) that would let you click any word in a note to automatically create a link, note from that link, and links from all occurrences of that word within the vault (or folder or even just notes that meet a specific search criteria).
I also think this plugin could helpfully generate a list of all words used within vault, note, heading, or even folder. This would assist and could be used in the word selection process, perhaps allowing you to select many before clicking commit then sitting back and letting it do its thing. I do have a macro and process that does this, but it is not elegant by any means.
Also, I do know you can use a mass search and replace replacing word with [[word]], but there is something exciting about being able to accomplish this with just a click. Plus the search and replace would break links that the word already occurred within unless you could design some pretty advanced regex. But, even that would likely not be 100% safe.