Why do many people use keywords as titles but get no inquiries?

Because what you're using are often "too broad terms." For example: carbon steel, steel pipes...

These terms have too little information. Users might be checking references, making comparisons, or even just learning—not here to buy.

When you use them directly as titles, the result is: many clicks, few inquiries, and poor lead quality.

The truly effective approach is to use keywords only as a framework and add purchasing signals to the title.

For example: Bulk purchase of carbon steel plates, H-beam steel for construction. One sentence can filter out non-buyers.

So the conclusion is clear:

1. Keywords are not the title, but they must be the core material of the title.

2. Strong purchasing terms can be used directly.

3. Broad terms must include purchasing signals like "supplier, price, bulk, export."

Google Search Ads compete not on copywriting but on who looks more like a page waiting for quotes.