For me it depends on the logic. If it’s a one-off number I need to reference, I’ll generally just link directly to another sheet. On the other hand, if I’m going to need to reference it fairly often on the sheet, I’ll usually copy it to a “parameters” region at the top that holds the relevant features of the scenario.
For example, yesterday I was projecting out how a product I’m working with affects capital structure, showing how debt, equity, and the optionality contract change over time. When looking at the chart, which is derived primarily from columns on the same sheet, it’s helpful to have a reminder of the key features of the scenario it is charting, and those parameters are set on a different sheet. So I copied them over.
On the other hand, sometimes I need to get some summary data from another sheet (take an average or a standard deviation or something), and I may often go ahead and just grab that directly without copying it over.
For me it depends on the data. Are we talking about data tabs being on the same sheet or different calculation tabs? I also use the Group feature a lot to embedde data that may be useful to see some of the time, but is better hidden most of the time.