You pay for a click and the visitor lands on a general page with seven menu items, no price, no proof for the thing they searched, and a form that asks for everything before it offers anything. Most leave. The few who enquire reach your inbox with no trace of the ad, keyword or poster that brought them, so next month’s budget is a guess.
A good landing page is narrow on purpose: one promise, the proof for it, the process, the price or the next step, and one form. It reads fully without JavaScript, so the assistants your buyers ask can describe the offer accurately too.
It matters more than it used to. 6sense reports that 85–95% of B2B buyers buy from their day-one shortlist. The page they land on has to earn that shortlist spot in one visit.