This happens to a lot of sites.
Iād start by looking at the keywords and phrases that are actually bringing in the traffic, not just the ones you want to rank for.
Are they mostly informational searches, commercial searches, awareness-stage questions, or decision-stage searches?
If most of the traffic is coming from people still trying to understand the problem, then the issue may be that your content isnāt helping them move to the next step. In that case, you probably need better internal links, clearer follow-up content, stronger examples, and a softer CTA than ābook a callā.
If people are landing on pages where they should be ready to enquire, then Iād look at the page itself. Is the offer clear? Is the messaging specific? Does the page explain why someone should trust you? Is the form asking for too much too soon?
So I wouldnāt see it as SEO vs ads straight away. Iād first work out whether you have the wrong traffic, the right traffic landing on the wrong content, or the right traffic landing on a page that isnāt doing enough to convert them.