If you value open-source principles and require a self-hostable solution, Penpot is your best bet. It's particularly suitable for privacy-conscious teams and those who prefer a tool built on open standards like SVG. However, if you need a rich plugin ecosystem and a polished user experience, Penpot might fall short, especially if your workflows depend on the extensive resources available in Figma.
On the other hand, Figma is ideal for product designers and larger design teams who thrive on collaboration, thanks to its real-time multiplayer capabilities and vast array of plugins and templates. While Figma offers a robust experience, it can become costly for many users as your team grows, and heavy files might affect performance on older machines. If you need a tool that supports offline work or want an open-source alternative, Figma would not be the right choice.