If you're a developer building custom canvas applications or part of a product team focused on interactive mockups, choose tldraw. Its polished infinite canvas and real-time collaboration features make it an excellent choice for creating dynamic designs and prototypes. However, keep in mind that commercial use requires a paid license and it isn't fully open source, which may be a dealbreaker for some.
On the other hand, if you are a product designer or leading a design team, opt for Figma. Its robust features for interface design, strong support for design systems, and extensive plugin ecosystem set it apart as the collaborative interface design standard. However, anticipate potential costs for larger teams and performance issues on lower-end machines. Avoid it if you need a completely open-source solution or if offline functionality is essential.