Somebody exported a keyword tool, pasted two hundred rows into one ad group, and now one ad has to be relevant to all of them. It cannot be, and the auction charges you for that.
A thousand keywords across well organised ad groups is fine. Two hundred in one group is not, because the single ad in that group cannot closely match most of them. Ad relevance is one of the documented components of ad quality, and it is where this shows up in your bill.
Adding the singular, the plural and three word orders of the same phrase does not multiply your reach, because they mostly match the same searches. What it does is split your data across five rows so none of them ever has enough traffic to tell you anything.
One broad keyword can pull in hundreds of different searches. So an account with fifty broad keywords is buying far more variety than one with three hundred exact ones, and the search terms report is the only place you can see it.
A small number of tightly related keywords per group, three ads that speak to that one theme, and a landing page that repeats the promise. It is duller than the two hundred row export and it is what produces a lower cost per lead.
This is teaching material and our own reading of public documentation, not advice for your specific account. Check anything important with your own specialist before you act on it.
Run the calculator, then tell us what it showed. We reply with what to fix first and why. No call, no pitch.