I can think of a few off the cuff. You're likely not running a model just for yourself. You have collaborators at other institutions that need data to compare

I can think of a few off the cuff. You're likely not running a model just for yourself. You have collaborators at other institutions that need data to compare or combine with something else. Your grant may require you distribute the output for use by other researchers. That could either entail being hosted by you or by an agency or other entity. But you still have to get the data to them. A reviewer for your publications may request the data. That brings up another point that the review process can be upwards of a year. Oftentimes you have to go through an exploratory data analysis, where you don't even know what your final analysis will entail.