This is disingenuous. Sure, the first X hours of working on a new project are a lot of fun and you can set up the framework for what you're doing and feel like you're making great progress.

But what you're missing is detail and quality. For example, I can set up the structure of my thesis by working out chapter titles, headings, subheadings and drafting bullet points per section. Straightforward. But doing the research and writing up takes years, it's often boring, laborious and the net addition to the document can be as low as a couple of hundred words a week. It doesn't mean the actual work is less valuable as time progresses.

Likewise let's consider a software development project. We can make grand strides in the first X weeks, gathering requirements, creating user stories, creating tasks, sprints, assigning work, setting deliverables, setting up the various ceremonies. But at some point it boils down to writing some code, often boring, time-consuming, detailed and slow. It doesn't mean the contributions made later in the project are any less valuable than the frantic hive of activity in the beginning.