These are all just tricks to reduce cost and make sure you get things done. You have competing constraints:

# You need to align the rest of your team on things: maybe you have marketing tied to real world events, you're hiring and training to a sales cycle. If you do it wrong you waste money

# You need to fight scope creep which happens with unbounded timelines

# You need to fight a minimal product that's not viable because it isn't done enough for your market

and more. The ideal is for the decision maker to constantly have full information on progress and make instantaneous minute adjustments to keep things going at full steam. But there's no way to have full information and there's no way to make instantaneous minute adjustments if you're not a one-man shop. So everything else comes from the organizational effort of trying to work with that.