I will give you a summarized answer out of the top of my head.
This answer is just a surface-level answer that can take pages of details if you want to go deeper:
You monetize the organic traffic depending on the keywords.
If there is a commercial intent behind those long-tail keywords you can monetize it either by offering the service or product yourself, or as an affiliate for those who offer it.
In the other case. If there is no commercial intent...
For example, if the keywords are just for informational intent, or news, or for the sake of entertainment:
You monetize them using ads placement near your articles/blog posts or discussion threads (Like in Reddit).
These ads can be adsense ads if your platform is accepted by Google adsense.
Or can be ads from one of the legit ads networks paying per impressions and clicks (Adsterra, Monetag, or any adult affiliate or ads network if the subject of your keywords is nsfw)