I assume you're referring to the EU Working Time Directive, which pretty much every major employer requires their staff to opt-out of when starting a new job?
It's a pointless EU law that just adds more paperwork to the recruitment process.
EDIT: For my part I've never worked for anyone asking for an opt-out, and I'd never sign an opt-out, and I would sue if I suspected an employer punished me for not signing an opt-out.
EDIT2: Here's the UK government advice on the opt-out [1]. Note: "Your employer can ask you to opt out, but you can’t be sacked or treated unfairly for refusing to do so. You can opt out for a certain period or indefinitely. It must be voluntary and in writing." Additionally there are exceptions for a very small set of types of workers [2].
[1] https://www.gov.uk/maximum-weekly-working-hours/weekly-maxim...
[2] https://www.gov.uk/maximum-weekly-working-hours/overview
Most major employers include the waiver as part of their onboarding process, and if you refuse to sign, although legally they cannot do anything, in practice you're going to start off on the wrong foot with that employer.
Likewise, if you turn around to your manager and refuse to work more than 48 hours (having not signed a waiver), although legally they cannot punish you for that, it's hardly going to help your career.
People are, by and large, aware of what they are getting into when they start a new job, and working hours are a factor in most remuneration calculations.
If the working hours are simply too much for you, then you should find a different job.
Thus, unemployment is reduced, more money is put into the economy and the full automation apocalypse is delayed for a little bit. And if another employee can't be paid, then that business is not really viable and should close.