A task is used further down in the workflow. When I think about planning features, they occur before development takes off. The task is used by the developer as they are breaking down the issue into smaller components.
task context of creating "task": developer as they break down a larger issue/epic into smaller pieces
You can see how the constant jumping between these two tools in the first scenario is super annoying, and also very risky as none of the changes you make in Figma are also automatically being updated in the same GitLab designs.
As a positive example of where this works well: Our VS Code GitLab Workflow extension allows users to not only see comments that were written inside the GitLab UI, but also allows these users to respond to these comments right from the IDE, the tool where they actually have to make these changes.