I've seen 3 major uses for estimations (besides the obvious forcing function to align on complexity/ideas among the team members): 1. Somebody really needs a t

I've seen 3 major uses for estimations (besides the obvious forcing function to align on complexity/ideas among the team members): 1. Somebody really needs a time-based estimate for the project, e.g. the customer wants feature X by a certain time and we need to figure out if it's feasible or not in that timeframe, or there's a certain external event (expo, or any other kind of marketing event) with a fixed date and we need to see if we can make it. This is usually rare in traditional product companies. 2. We need to see if the project is worth it, in general. Maybe it's just too much effort to even consider. 3. We need to prioritize a couple of projects/opportunities. ICE/RICE comes into play, and we need to stack rank based on return on investment. Relative effort in meaningless units (tshirt, cups, etc.) make perfect sense here.