The most common cause
A five-page website can be found five ways. A catalogue site with one page per product can be found thousands of ways. That structural difference explains most cases of a well-designed site producing no enquiries — the site is not bad, it is invisible, because it publishes almost nothing a buyer would search for.
Santosh Electricals went from a price-list PDF to 1,479 indexed pages and saw ₹4,00,000 in organic revenue in 10 days. The design was not the variable.
The other four causes, in order
You rank for terms nobody buys on — "best quality supplier" instead of the part numbers your customers actually type. Your pages take too long to load on a phone on mobile data. There is no obvious next action, so an interested visitor has nothing to do. Or enquiries do arrive and nobody follows them up, which looks identical to no enquiries from where you are standing.
How to check which one it is
Open Google Search Console. If it shows almost no impressions, the problem is structural — there is nothing indexed to be found. If impressions are healthy but clicks are not, the problem is your titles and descriptions. If clicks are healthy but enquiries are not, the problem is on the page. Each of those is a different fix, and guessing between them wastes months.