Metal tools are needed to make it at all feasible, because they'd be spending even MORE time replacing tools broken or damaged by the crafting processes. It's why literally a third of our activity is making tools, whenever we build rafts, even our current simple rafts which require braiding fibers into rope and cutting down small trees and branches, uses a lot of tools.Metal tools are wholly unnecesary. It is entirely possible to do so without them.
And, no, I entirely disagree that forcing artisans to learn to fish would stop them from time consuming methods of making boats. It'd do the opposite -- it'd force them to innovate to make their training easier.
If we forced our artisans to go fish we'd be working with lower quality and lower quantity tools, disincentivizing projects which consume many tools for better results, as the production cycle is less efficient.