It's usually traded for no-lockout, closed shop and dues checkoff. If they don't get those,then it's an open shop where reps are spending all their time collecting dues and the employer can lay everyone off without just cause.

Sometime they negotiate contracts without it for the sake of a first contract, but it's rare, and tends to reduce membership rates.

There's a cool middle ground UE does sometimes where they get language about striking over grievances or safety issues.

IBT has another cool workaround where they can respect other unions' picket lines.