Hi isk,
It's important to have job-seeking workers WHERE YOU NEED THEM. If a workplace has NO workers living nearby, the labor recruiter won't find anybody to hire and will just give up.
At least 3 nearby occupied huts seems to be the minimum for a building to find workers. After the initial new hires, the industry will take additional workers from anywhere in the city (perhaps learning about the available jobs by word-of-mouth from the early workers).
There are two techniques to get these important initial workers -- one is the "labor access road" that leads to a nearby residential neighborhood -- the labor access road does NOT have to connect with the "loop" within the neighborhood; it just has to touch the backs of a few houses.
The other technique, which I prefer, is to have "housing seeds" in the industrial district itself. This provides the initial workers, and as I said, once that's done additional workers will be taken from any part of the city. About 3 nearby occupied huts is enough to get going, but you can always provide even more just to make sure the buildings have reliable access to workers. (I don't bother upgrading these "seeds" much.)
But just because an industry finally gets its workers, you can't remove the seeds -- they are still needed.
Sometimes a new building will find workers, then a short while later, become unstaffed. Additional seeds can help prevent this. This is only a problem early in the life of the workplace; once the district becomes established, the "additional" houses can be razed to make room for more buildings.
Storage Yards and Ferry Landings are particularly sensitive to finding then losing workers. Don't let that happen!
Just one more thing: if people start EMIGRATING from a city, those living in cheaper housing will leave first. This could result in "seeds" being abandoned, buildings having no workers, and unemployment skyrocketing because of all the people in the neighborhoods not having functioning industries to employ them. The cure, other than preventing it from happening, is to build workplaces (like Work Camps) in the neighborhoods until everybody's back to work again. Work Camps in "nice" areas are an abomination, but once the economy is going again, they can be cleared away.
Henipatra
[This message has been edited by Henipatra (edited 01-23-2021 @ 00:32 AM).]