The practical value of related-keyword research today comes less from the original LSI technique and more from how modern natural language processing evaluates content meaning.
Search Engines Have Moved Well Beyond Simple Term Matching
Contemporary language models can understand context, synonyms, and conceptual relationships far more sophisticatedly than the original LSI method ever could.
The Practical Takeaway Hasn't Changed Much
Whether the underlying technology is literally LSI or a modern language model, covering a topic's genuine related vocabulary remains a sound content practice either way.
Don't Get Distracted by the Technical Debate
For the purpose of writing better, more comprehensive content, the exact algorithm behind the scenes matters less than actually understanding and covering your topic well.
Next step: Use the LSI Tool to pull related terms as a practical starting point, regardless of the underlying algorithm debate.