Although still not officially used, there are indications that this will become accepted by AI tools and will help index your site better. This tool might help you get ahead with such tools or it might turn out to be a waste of time, who knows. If you have 5 minutes to spare, give it a try - it won't cause any damage, that's for sure.
It's something new and not YET widely accepted, but I do remember the times when we laughed at Google and thought Altavista was the king of universe...

I was asked to build it for a client and am just sharing with the community so please don't ask ME how this would improve your SEO.

Does the whole concept of the llms.txt file make sense? That's up to you to decide.

Some material possibly worth reading:
https://llmstxt.org/
https://www.semrush.com/blog/llms-txt/

Submitting as a plugin, but you can find the latest version on Github: https://github.com/zenexpert/zx-llms-txt-generator