Why didn't Biden invoke Taft-Hartley to delay the strike?

That would have delayed the strike until Christmas, and best served consumers, retailers and rank and file Longshoremen.

A prolonged strike can destroy some retail businesses by disrupting their supply chain during what should be their busiest days. Also no paychecks for workers affected, including longshoremen, in the run-up to Christmas.

Apparently the $millions that labor unions pump into the Democrat party buys union leaders special consideration.