> The “performative” is why doesn’t Tesla just sign a union agreement

Because very few (none?) employees working for Tesla are actually on strike. There are a lot of postal employees, dockworkers, etc on strike, but not many from Tesla.

It appears that the IF Metall wants Tesla to sign a collective agreement, but neither Tesla nor most (all?) of Tesla's employees want that. As far as I can ascertain, the union's only grievance against Tesla is that they do not have a collective bargaining agreement (not pay, not conditions).

IF Metall has gotten so little traction that they are offering even non-member Tesla employees 130% of normal pay to go on strike, and also publicly talking about sanctions against member employees who continue to show up to work.