What do you think people working in construction actually do when the project is done? Just spend the rest of their life homeless? No, they go to the next project.

The problem is that when the lobbyists are pitching these builds to the local town councils, the "create X jobs" part of the marketing is very carefully worded to heavily imply "X long term jobs will be created" while also not actually directly saying "X long term jobs will be created". They want the council members thinking X long term jobs, but want to avoid legal liability for lying later when the reality of X was 99% temporary jobs lasting 6-12 months and 1% long term jobs for the community.

And few council members seem to have been snookered enough yet that they know to ask the marketing lobbyist the pointed question: "How many of those X jobs are long term and will persist after construction and build-out is completed?".