How do I build "prototype illustrations" for your landing page?

I am trying to build a landing page/waitlist for an idea I came up with. I don't want to go coding without any form of validation, so I plan to make this landing page.

I'd like to have some "prototype illustrations" something like the ones you see on slack.com's homepage: https://a.slack-edge.com/8606940/marketing/img/homepage/post-experiment/inline/animations/webm/slack-connect.webm

I don't want to spend time and code a full blown - detailed UI and screen record my PC, rather just some sort of abstract illustrations (like the one I linked above) that could display the major UI elements/color scheme/functionality.

I don't think Figma (or other wireframing tools) is the right tool for this. Do I need to use some graphics design tool for this? I don't have any experience with such tools. What would you recommend? I want to be able to build video/gif of the "prototype" not just still images/screenshots.

Thanks..