Your estimator spent half a day on a quote: site visit, BOQ, supplier prices, a tidy PDF. It goes out on a Tuesday. The client says thanks. Then nothing happens, because the estimator is already on the next three quotes and the salesperson is out on site. Two weeks later someone remembers to call, and the client says they went with another supplier last week.
Follow-up is the step everyone agrees matters and nobody owns. It lives in individual inboxes and memories. Big quotes get chased because they're on someone's mind; the steady flow of mid-sized quotes, which together are most of the revenue, quietly expires without a single reminder.
When it is done, it's done badly. The same "just following up" email, sent whenever someone has a spare minute, with no idea whether the client opened the quote, asked a question, or already replied to a colleague. Some clients get chased three times in a day; others never hear back at all.
So the quote pipeline you report on isn't real. Quotes sit as "open" long after the client has decided, nobody can say which ones are worth a phone call today, and management has no way to see how many were lost to silence rather than price.