Most contractor jobs come from referrals. A neighbor recommends you. A past customer tells their cousin. That part still works. But before that cousin picks up the phone, they Google your business name. If what comes up is a barely-filled Google listing, an outdated 2014 site, or nothing at all, the referral leaks.
The customer types in your competitor's name next. Or they click the top organic result, which is rarely yours. Or they call the AC company with 200 five-star reviews and a fast-loading mobile site, even though their neighbor told them to call you.
Your reputation does the work. A website is what closes the sale.