The Conservatives do not like unions. Unions are about ensuring members get to work, they are not in favour of bankruptcies of employers. They are interested in a fair deal for workers and thanks to the laws imposed by the Conservatives, strike action for many industries has more of a mandate than Liz Truss did when she was elected by a few Conservative members!
A huge example of why unions are important is seen with Elon Musk. His actions to employees are disgusting and should not be allowed. I accept that he can get away with this abroad, but thanks to unions, other employers cannot act like this here. Unless they own a ferry company.