If you're driving visitors to your SaaS landing page from any marketing channel, you need to ensure they're converting into customers on your landing page. Otherwise, the money and time you're spending on marketing are being lost at the most critical moment.
If you can increase the percentage of visitors on your landing page that become customers, you'll see a significant boost in your overall marketing ROI.
You can also A/B test different landing page variations to see what works best with your audience, or book a landing page conversion roast from an expert.
When testing, it's always best to start with big changes. Focus on a hypothesis (eg. I noticed this, so I should do this and should expect to see this... ), and optimize to learn more about your customers. Testing will give you the data you need to refine your pages and make them their best.