You realise that the Keystone pipeline extension hadn't even started yet? And that the job would have only been for a few months?Is Biden leaving any stone unturned in his endeavors to crush our economy and jobs?
The people who would have built it would have been just as 'unemployed' once it was done?
Basically what you're describing is the nature of contractor work. They lost the contract. If that was their sole breadmaker in life, they would be in the same position within a year anyway after the job was done.
Maybe if they wanted more stable work they should have made better life choices