Well, yes. Estimation is design. Only if you call it "estimation" the engineer who's been berated into crunch-overtime for a miss in the past won't want to do

Well, yes. Estimation is design. Only if you call it "estimation" the engineer who's been berated into crunch-overtime for a miss in the past won't want to do it and will do it badly when forced, and the cheap company owner whose own behaviours drive teams to estimate badly ("that estimate's huge, I'm not paying that, estimate it again but smaller") won't have had good experiences to understand why that design phase is valuable. There needs to be enough time in the schedule to design to an adequate level for the problem at hand. You don't necessarily want as clear a picture as possible, but you do want as clear a picture as necessary.