As we all use ClickUp tools in different ways, i think the limitation on what custom fields can be used in the personal list (and LineUp) put some restrictions.

I and the managers in our team use LineUps to delegate "objective" tasks to our devs and designers as generally things to focus on that week where as the details of the task are in their agendas and such, without custom fields in the lineup some of the details are missed and make it more difficult to to keep in mind what's happening