For collaborative interface design and established workflows, Figma is clearly the better choice. It's ideal for product designers and design teams who require robust design-system support and a multitude of plugins. However, keep in mind that as your team grows, the cost of editor seats can become significant, and large design files may slow down lower-end machines. If your focus is on detailed collaborative work in a mature environment, Figma is the way to go.
On the other hand, if you're a developer looking to create custom canvas applications or prototypes, tldraw could be more suited to your needs. It offers an innovative infinite canvas for real-time collaboration and the ability to convert sketches into functional UI elements. However, be aware that it's not fully open source, and if you plan to use it commercially without watermarks, you'll need a paid license. Choose tldraw if your emphasis is on customizability and exploratory design rather than a comprehensive design suite.